This document discusses different boost converter designs for photovoltaic generators. It compares a basic MOSFET-based boost converter to a proposed couple-coils boost converter. The basic converter uses discrete components like an inductor, freewheeling diode, and power MOSFET switch. Loss analyses are performed on these components. A coupled-coils design is proposed to minimize losses by integrating a low voltage MOSFET and very low resistance inductor. The goal is to design high efficiency converters for medium and high voltage photovoltaic systems connected to 230V AC grids.
This work highlights a modular power conditioning system (PCS) in photovoltaic (PV) applications which consists with a DC-DC converter. The converter is able to regulate and amplify the input DC voltage produced by the PV panal. The implementation of Mosfet as bidirectional switch on the converter yields greater conversion ratio and better voltage regulation than a conventional DC-DC step up converter and PWM resonant converter. It also reduces the switching losses on the output DC voltage of the converter, as the MOSFET switches on primary winding of converter switch on under ZVS conditions. The proposed resonant converter has been designed, with the modification of series resonant converter and PWM boost converter that utilizes the high frequency of AC bidirectional switch to eliminate the weaknesses of used converters. The topology of the proposed converter includes the mode of operations, designing procedure and components selection of the new converter elements. This topology provides a DC output voltage to the inverter at range of about 120Vac-208 Vac.
A Novel Three Phase Multi-string Multilevel Inverter with High DC-DC Closed o...rnvsubbarao koppineni
this inverter reduces
number power devices and high performances.
Before this inverter provide a high step up DC-DC
converter with PI controller for better conversion
efficiency and to improve the output dc voltage of
varies renewable energy sources. This multi-string
multilevel inverter consists of six switches only
instead of eight switches in cascaded H-bridge
multilevel inverter in order to reduce conversion
losses. The main objective of this paper is to save
cost and size by removing any kind of transformer
as well as reducing the power devices
Simulation of various DC-DC converters for photovoltaic systemIJECEIAES
This work explains the comparison of various dc-dc converters for photovoltaic systems. In recent day insufficient energy and continues increasing in fuel cost, exploration on renewable energy system becomes more essential. For high and medium power applications, high input source from renewable systems like photovoltaic and wind energy system turn into difficult one, which leads to increase of cost for installation process. So the generated voltage from PV system is boosted with help various boost converter depends on the applications. Here the various converters are like boost converter, buck converter, buck-boost converter, cuk converter, sepic converter and zeta converter are analysed for photovoltaic system, which are verified using matlab / simulink.
High Step-Up Converter with Voltage Multiplier Module for Renewable Energy Sy...IJRES Journal
In this project, A novel high step-up converter, which is suitable for renewable energy system, is proposed.Through a voltage multiplier module composed of switched capacitors and coupled inductors, a conventional interleaved boost converter obtains high step-up gain without operating at extreme duty ratio.The configuration of the proposed converter not only reduces the current stress but also constrains the input current ripple, which decreases the conduction losses and lengthens the lifetime of the input source. In addition, due to the lossless passive clamp performance, leakage energy is recycled to the output terminal. Hence, large voltage spikes across the main switches are alleviated, and the efficiency is improved.
Analysis of Fuel Cell Based Multilevel DC-DC Boost Converter for Induction MotorIJMTST Journal
In this paper new topologies and interleaving modulation concepts for multilevel DC-DC boost converter
enabling a significantly less loss and a reduced chip size of the power semiconductors are proposed. The
distributed generation (DG) systems based on the renewable energy sources have rapidly developed in
recent years. These DG systems are powered by micro sources such as fuel cells, photovoltaic (PV) systems,
and batteries. Fuel cells are considered to be one of the most promising sources of distributed energy because
of their high efficiency, low environmental impact and scalability. Non-isolated high step-up DC-DC
converters are required in the industrial applications. Many of these conventional DC–DC converters have the
disadvantages of operating at high duty-cycle, high switch voltage stress and high diode peak current. A
three-level step up converter is implemented to boost the fuel cell stack voltage of 96V to 340V. The proposed
converter consists a system of fuel cell based Multilevel DC-DC converter with PI controller is modeled and
simulated by using Matlab/Simulink.
The intention of this paper is to identify a suitable controller for closed loop multi converter system for multiple input sources and to improve time response of high-gain-step up-converter. Closed-loop Multi Converter System (MCS) is utilized to regulate load-voltage. This effort recommends suitable-controller for closed-two loop-controlled-SEPIC-REBOOST Converter fed DC motor. The estimation of the yield in open-two loop and closed- two-loop-circuit has been done using MATLAB or Simulink. Closed-two loop-control of Multi Converter System with Propotional+Integral (PI)- Propotional+Integral (PI) and Proportional+Resonant (PR) - Proportional+Resonant (PR) Controllers are investigated and their responses are evaluated in conditions of rise time, peak time, settling time and steady state error. It is seen that current-mode PR-PR controlled MCS gives better time domain response in terms of motor speed. A Prototype of MCS has been fabricated in the laboratory and the experimental-results are authenticated with the simulation-results.
This work highlights a modular power conditioning system (PCS) in photovoltaic (PV) applications which consists with a DC-DC converter. The converter is able to regulate and amplify the input DC voltage produced by the PV panal. The implementation of Mosfet as bidirectional switch on the converter yields greater conversion ratio and better voltage regulation than a conventional DC-DC step up converter and PWM resonant converter. It also reduces the switching losses on the output DC voltage of the converter, as the MOSFET switches on primary winding of converter switch on under ZVS conditions. The proposed resonant converter has been designed, with the modification of series resonant converter and PWM boost converter that utilizes the high frequency of AC bidirectional switch to eliminate the weaknesses of used converters. The topology of the proposed converter includes the mode of operations, designing procedure and components selection of the new converter elements. This topology provides a DC output voltage to the inverter at range of about 120Vac-208 Vac.
A Novel Three Phase Multi-string Multilevel Inverter with High DC-DC Closed o...rnvsubbarao koppineni
this inverter reduces
number power devices and high performances.
Before this inverter provide a high step up DC-DC
converter with PI controller for better conversion
efficiency and to improve the output dc voltage of
varies renewable energy sources. This multi-string
multilevel inverter consists of six switches only
instead of eight switches in cascaded H-bridge
multilevel inverter in order to reduce conversion
losses. The main objective of this paper is to save
cost and size by removing any kind of transformer
as well as reducing the power devices
Simulation of various DC-DC converters for photovoltaic systemIJECEIAES
This work explains the comparison of various dc-dc converters for photovoltaic systems. In recent day insufficient energy and continues increasing in fuel cost, exploration on renewable energy system becomes more essential. For high and medium power applications, high input source from renewable systems like photovoltaic and wind energy system turn into difficult one, which leads to increase of cost for installation process. So the generated voltage from PV system is boosted with help various boost converter depends on the applications. Here the various converters are like boost converter, buck converter, buck-boost converter, cuk converter, sepic converter and zeta converter are analysed for photovoltaic system, which are verified using matlab / simulink.
High Step-Up Converter with Voltage Multiplier Module for Renewable Energy Sy...IJRES Journal
In this project, A novel high step-up converter, which is suitable for renewable energy system, is proposed.Through a voltage multiplier module composed of switched capacitors and coupled inductors, a conventional interleaved boost converter obtains high step-up gain without operating at extreme duty ratio.The configuration of the proposed converter not only reduces the current stress but also constrains the input current ripple, which decreases the conduction losses and lengthens the lifetime of the input source. In addition, due to the lossless passive clamp performance, leakage energy is recycled to the output terminal. Hence, large voltage spikes across the main switches are alleviated, and the efficiency is improved.
Analysis of Fuel Cell Based Multilevel DC-DC Boost Converter for Induction MotorIJMTST Journal
In this paper new topologies and interleaving modulation concepts for multilevel DC-DC boost converter
enabling a significantly less loss and a reduced chip size of the power semiconductors are proposed. The
distributed generation (DG) systems based on the renewable energy sources have rapidly developed in
recent years. These DG systems are powered by micro sources such as fuel cells, photovoltaic (PV) systems,
and batteries. Fuel cells are considered to be one of the most promising sources of distributed energy because
of their high efficiency, low environmental impact and scalability. Non-isolated high step-up DC-DC
converters are required in the industrial applications. Many of these conventional DC–DC converters have the
disadvantages of operating at high duty-cycle, high switch voltage stress and high diode peak current. A
three-level step up converter is implemented to boost the fuel cell stack voltage of 96V to 340V. The proposed
converter consists a system of fuel cell based Multilevel DC-DC converter with PI controller is modeled and
simulated by using Matlab/Simulink.
The intention of this paper is to identify a suitable controller for closed loop multi converter system for multiple input sources and to improve time response of high-gain-step up-converter. Closed-loop Multi Converter System (MCS) is utilized to regulate load-voltage. This effort recommends suitable-controller for closed-two loop-controlled-SEPIC-REBOOST Converter fed DC motor. The estimation of the yield in open-two loop and closed- two-loop-circuit has been done using MATLAB or Simulink. Closed-two loop-control of Multi Converter System with Propotional+Integral (PI)- Propotional+Integral (PI) and Proportional+Resonant (PR) - Proportional+Resonant (PR) Controllers are investigated and their responses are evaluated in conditions of rise time, peak time, settling time and steady state error. It is seen that current-mode PR-PR controlled MCS gives better time domain response in terms of motor speed. A Prototype of MCS has been fabricated in the laboratory and the experimental-results are authenticated with the simulation-results.
Proposed PV Transformer-Less Inverter Topology Technique for Leakage Current ...IJPEDS-IAES
Importance and demand of using renewable energy is dramatically escalated globally. Hence, the use of renewable energy is going to touch in peak. This demand is varying according to the site choosing. For instance, Wind is preferable where air is following highly as well as solar recommended place is high sun ray reducing places. Especially, the renewable system is highly recommended for electrification issues where it’s possible to produce the electricity for fulfilling rural and remote areas electricity problem. The photovoltaic (PV) panel of connecting with transformer based system is popular where some limitations are occurred especially cost and weight. In contrast, in this paper is focusing these issues where the transformer-less inverter system is used. Here will discuss some transformer-based and transformer-less inverter topologies and the leakage current issue which is occurred when transformer-less inverter system is used. Moreover, here is proposed a topology for reducing the leakage current after doing switching technique in both 50% and 75% duty cycle where output voltage remains quite same.
Design and Simulation of Efficient DC-DC Converter Topology for a Solar PV Mo...Sajin Ismail
Modulated Integrated Converter systems are considered to be the new and global turning point in the field of
Solar PV systems. These converters are highly recognised for its modular size and compact nature and they are supposed to
be attached directly with each PV module and since one PV module is having the power rating of a few watts ranging from
0-500Ws, the design rating would be in the same range and thus the most vital condition in such a design is efficiency
under these relatively low loads. In this paper an isolated interleaved boost converter topology is considered in the DC-DC
section and which is designed and simulated for a specific power rating (250W) and the efficiency is analysed with varying
load conditions and compared with the target efficiency of the system.
DESIGNING AND IMPLEMENTATION OF BI - DIRECTIONAL ISOLATED FULL BRIDGE CONVERTEREditor IJMTER
In the renewable energy systems, the exchange of power from the source to the load and
vice-versa have conventionally been implemented with two uni-directional converters; each
processing the power in one direction. To improve the energy quality in such systems, bidirectional
DC-DC converters are used to charge/discharge the energy storage systems. This paper proposes the
bidirectional DC-DC converter which employs the two full single phase bridge converter
configuration on the both sides of the isolating transformer. The high side converter is controlled as
step down and the low side converter is controlled as step up. At a given instant of time, only one
converter is controlled and other acts as diode bridge converter. The proposed system is
characterized by good dynamic properties and high efficiency because of low switching losses.
Using the same power components for achieving bidirectional flow of power in the symmetrical
circuit topology provides a simple, efficient and galvanic ally isolated that is especially attractive for
use in battery charging/discharging circuits.High frequency isolation transformer plays an important
role in achieving galvanic isolation and also for reducing the system size, weight and cost. Power
MOSFET switches, provided with snubber circuit and PI filter at the output side are employed to
reduce the ripple and for voltage regulation in this proposed thesis.
International Journal of Engineering Research and Development (IJERD)IJERD Editor
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
yahoo journals, bing journals, International Journal of Engineering Research and Development, google journals, hard copy of journal
Push-Pull Converter Fed Three-Phase Inverter for Residential and Motor LoadIJPEDS-IAES
The proposed paper is an new approach for power conditioning of a PV
(photo-voltaic) cell array. The main objective is to investigate an approach to
provide and improve the delivered electric energy by means of power
conditioning structures with the use of alternative renewable resources
(ARRs) for remote rural residential or industrial non-linear loads. This
approach employs a series-combined connected boost and buck boost DCDC
converter for power conditioning of the dc voltage provided by a photovoltaic
array. The input voltage to the combined converters is 100 V
provided from two series connected PV cells, which is converted and
increased to 200 V at the dc output voltage. Series-combined connected
boost and buck-boost DC-DC converters operate alternatively. This helps to
reduce the input ripple current and provide the required 400 Vdc on a
sinusoidal PWM three-phase inverter. Analysis of the two series-combined
DC-DC converters is presented along with simulation results. Simulations of
the series-combined DC-DC converters are presented with an output DC
voltage of 200 V and a maximum output load of Po=600 W.
Real Time Implementation of Variable Step Size Based P&O MPPT for PV Systems ...IJPEDS-IAES
Nowadays Solar energy is an important energy source due to the energy crisis and environment pollution. Maximum power point tracking (MPPT) algorithm improves the utilization efficiency of a photovoltaic systems. In this paper an improved P&O MPPT algorithm is developed and simulated using MATLAB / SIMULINK to control the DC/DC buck converter. The obtained simulink model is also verified using dspace tool. Both the simulated and experimental results are validated by also comparing them with conventional MPPT methods. The performance measures show the increase in the efficiency of PV system by the proposed model.
High gain dc-dc step up converters have been used in renewable energy systems, for example, photovoltaic grid connected system and fuel cell power plant to step up the low level dc voltage to a high level dc bus voltage. If the conventional boost converter is to meet this demand, it should be operated at an extreme duty cycle (duty cycle closes to unity), which will cause electromagnetic interference, reverse recovery problem and conduction loss at the power switches. This paper proposes a class of non-isolated dc-dc step up converters which provide very high voltage gain at a small duty cycle (duty cycle < 0.5). Firstly, the converter topologies are derived based on active switched inductor network and combination of active and passive switched inductor networks; secondly, the modes of operation of proposed active switched inductor converter and combined active and passive switched inductor converter are illustrated; thirdly, the performance of the proposed converters are analyzed mathematically in details and compared with conventional boost converter. Finally, the analysis is verified by simulation results.
High Proficiency Grid ConnectedPhotovoltaic Power Generation SystemIJRES Journal
Solar energy hasbecomepopular nowadays and desire for clean energy. Since the solar radiation on no occasion remains constant,it keeps on insecure throughout the day. The need of the hour is to distribute a constant voltage to the grid irrespective of the deviation in temperatures and solar insolation. The inverter is designed from a boost converter along with a line frequency. The voltage from the boost converter is fedto the grid through inverter. In this proposed method high efficiency can be achievedby using only one switch functioning at high frequency at a time. The converter uses IGBT and ultra-fast reverse recovery diode. The simulation and experiment results are verified using MATLAB/Simulink software.
Z - Source Multi Level Inverter Based PV Generation SystemIJERA Editor
In this paper a novel technique of Z-Source multilevel Inverter based PV Generation system is implemented and simulated using MATLAB-Simulink simulation software. The Photovoltaic cells are healthier option for converting solar energy into electricity. Due to high capital cost and low efficiency PV cells have not yet been a fully smart choice for electricity users. To enhance the performance of the system, Z-Source multi level inverter can be used in place of conventional Voltage Source Inverter (VSI) in Solar Power Generation System. The PV cell model is developed using circuit mathematical equations. The Z-Source multilevel inverter is modeled to realize boosted DC to AC conversion (inversion) with low THD. Outcome shows that the energy conversion efficiency of ZSMLI is a lot improved as compared to conventional voltage Source Inverter (VSI). By doing FFT analysis we can know the total THD.
In this paper a buck-boost dc-dc converter for pv application is proposed, which is mainly composed of a buck – boost converter, PV panel, load and a battery. Existing dc-dc converter can convert the power from the PV panel, but unfortunately the PV panel can only provide power when there is a high intensity of light. In order to provide power supply to the load without any interruption, buck-boost dc-dc converter is introduced. The power intermittency issue of PV panel can be overcome with the aid of a secondary supply which is in this case, the batter. The integration system between the primary and the secondary supply is controlled by a simple proposed control scheme. Battery act as a power in the low voltage side while PV panel is taking over in the high voltage side. Buck-boost converter is operated either is buck or boost mode according to the performance of the PV panel. This paper is presented the simple control scheme to decide the mode suitable for the buck and boost mode. Various conditions are simulated to verify the working operation of the buck-boost converter and to representing solar panel in real life. Simulation and experimental are carried out to verify the system.
Performance enhancement of DC/DC converters for solar powered EV IJECEIAES
The paper initially presents the essential drive arrangement required for electric vehicle. It requests high power bidirectional stream ability, with wide info voltage range, and yield voltage of vitality stockpiling gadgets, for example, super capacitors or batteries shift with the adjustment in stack. At that point the tenacity and outline of previously mentioned converter is proposed in this paper. The converter which relates a half extension topology, has high power stream ability and least gadget focuses on that can appropriately interface a super capacitor with the drive prepare of a crossover electric vehicle. Besides, by contrasting the fundamental qualities and applications with some ordinary bidirectional DC/DC converter, the proposed converter has low gadget rating and can be controlled by obligation cycle and stage move. Finally, the most essential attributes of this converter is that it utilizes the transformer spillage inductance as the essential vitality exchange component and control parameters, Simulation waveforms in light of MATLAB recreation are given to exhibit the integrity of this novel topology, and this converter is additionally reasonable for high power application, specifically to control the charge-release of super capacitors or batteries that can be utilized as a part of cross breed solar based electric vehicle.
Research Inventy : International Journal of Engineering and Scienceinventy
Research Inventy : International Journal of Engineering and Science
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed
Hysteresis SVM for Coupled Inductor Z Source Diode Clamped 3-Level Inverter B...IAES-IJPEDS
Due to its advantages such as it can defeat problems such as leakage current
and insertion of DC in the grid and provides low stress on power devices,
Diode-clamped three-level inverter (DCTLI) is habitually used in
transformerless photovoltaic (PV) connected to grid network. But it still has
a problem of shoot-through which dwells in its legs, so its operation not
reliable. Z source network is employed to permit operation without shoot
through risk and improve its reliability. Coupled inductors are replaced the
line transformers in to attain lower cost, reduced size, and improved its
reliability and efficiency. Coupled inductor which avoids leakage current
problem and losses. It employs coupled inductor z source diode clamped
three level inverter (CI-Z-DC-TLI) to boost the voltage and further progress
the consistency of the proposed system by avoiding the shoot through the
problem. The proposed system assures that common-mode voltage
and shoot-through risk is avoided. Moreover, controlling DC-TLI with
Hysteresis SVM algorithm which improves output voltage and current
control. Simulation and experimental results of this proposed system were
analyzed using MATLAB environment and FPGA hardware.
Analysis and Design of Solar Photo voltaic Grid Connected Inverterijeei-iaes
This paper presents common mode voltage analysis of single phase grid connected photovoltaic inverter. Many researchers proposed different grid tie inverters for applications like domestic powering, street lighting, water pumping, cooling and heating applications, however traditional grid tie PV inverter uses either a line frequency or a high frequency transformer between the inverter and grid but losses will increase in the network leading to reduced efficiency of the system. In order to increase the efficiency, with reduced size and cost of the system, the effective solution is to remove the isolation transformer. But common mode (CM) ground leakage current due to parasitic capacitance between the PV panels and the ground making the system unreliable. The common mode current reduces the efficiency of power conversion stage, affects the quality of grid current, deteriorate the electric magnetic compatibility and give rise to the safety threats. In order to eliminate the common mode leakage current in Transformerless PV systm two control algorithms of multi-carrier pwm are implemented and compared for performance analysis.The shoot-through issue that is encountered by traditional voltage source inverter is analyzed for enhanced system reliability. These control algorithms are compared for common mode voltage and THD comparisons. The proposed system is designed using MATLAB/SIMULINK software for analysis.
Performance numerical evaluation of modified single-ended primary-inductor c...IJECEIAES
Single-ended primary-inductor converter (SEPIC) was considered a good alternative to a DC-DC converter for photovoltaic (PV) systems. The SEPIC converter can operate with an input voltage greater or less than the regulated output voltage, or as a step-up or step-down. As a step-up converter, SEPIC boosts PV voltage to specific levels. However, gain limitation and voltage stress continue to reduce the efficiency of conventional SEPIC converters. Because of this, researchers created a modified SEPIC converter to improve performance. In this paper, six modified SEPIC converters were compared and evaluated. To compare fairly, all modified SEPIC converters are nonisolated and use a single switch. Power simulator (PSIM) software was used to simulate each converter with a BISOL BMO-250 PV module and maximum power point tracking (MPPT) P&O controller. The converter with the highest static voltage gain and lowest duty cycle has been identified. It results in up to ten times voltage increment with a 0.8-duty ratio. All topologies have the same voltage stress, with maximum and minimum values of 30.1 and 29.5 V, respectively. On the other hand, each topology produces different average efficiencies, with the highest and lowest efficiency at 99.5% and 97.2%, respectively.
Fuzzy based control of Transformer less Coupled inductor based DC-DC converterIJERA Editor
Most of the industrial applications use any one of the basic DC-DC converter configurations namely buck,
boost, buck–boost, and Cuk converters. These converters are non-isolating converters. Buck-boost converters
use inductors for storing energy from the source and release the same to load or output. This results in high
stress across magnetic components. This drawback restricts usage of buck-boost converters to low power
applications. Flyback converters popularly have known as buck-boost converters uses transformers for
achieving wide range of step down and step up voltages. Coupled inductor based converters or tapped inductor
based converters are used for achieving wide input – wide output conversion ratios. Coherent transition between
step-down and step-up modes is achieved by a proper control scheme. This paper proposes fuzzy logic based
closed loop control scheme for control of converter switches. Theoretical derivations of control parameters with
their membership values, mamdani based rules for development of fuzzy rules and simulation results of a
coupled inductor based DC-DC converter using MATLAB / SIMULINK are concluded.
Proposed PV Transformer-Less Inverter Topology Technique for Leakage Current ...IJPEDS-IAES
Importance and demand of using renewable energy is dramatically escalated globally. Hence, the use of renewable energy is going to touch in peak. This demand is varying according to the site choosing. For instance, Wind is preferable where air is following highly as well as solar recommended place is high sun ray reducing places. Especially, the renewable system is highly recommended for electrification issues where it’s possible to produce the electricity for fulfilling rural and remote areas electricity problem. The photovoltaic (PV) panel of connecting with transformer based system is popular where some limitations are occurred especially cost and weight. In contrast, in this paper is focusing these issues where the transformer-less inverter system is used. Here will discuss some transformer-based and transformer-less inverter topologies and the leakage current issue which is occurred when transformer-less inverter system is used. Moreover, here is proposed a topology for reducing the leakage current after doing switching technique in both 50% and 75% duty cycle where output voltage remains quite same.
Design and Simulation of Efficient DC-DC Converter Topology for a Solar PV Mo...Sajin Ismail
Modulated Integrated Converter systems are considered to be the new and global turning point in the field of
Solar PV systems. These converters are highly recognised for its modular size and compact nature and they are supposed to
be attached directly with each PV module and since one PV module is having the power rating of a few watts ranging from
0-500Ws, the design rating would be in the same range and thus the most vital condition in such a design is efficiency
under these relatively low loads. In this paper an isolated interleaved boost converter topology is considered in the DC-DC
section and which is designed and simulated for a specific power rating (250W) and the efficiency is analysed with varying
load conditions and compared with the target efficiency of the system.
DESIGNING AND IMPLEMENTATION OF BI - DIRECTIONAL ISOLATED FULL BRIDGE CONVERTEREditor IJMTER
In the renewable energy systems, the exchange of power from the source to the load and
vice-versa have conventionally been implemented with two uni-directional converters; each
processing the power in one direction. To improve the energy quality in such systems, bidirectional
DC-DC converters are used to charge/discharge the energy storage systems. This paper proposes the
bidirectional DC-DC converter which employs the two full single phase bridge converter
configuration on the both sides of the isolating transformer. The high side converter is controlled as
step down and the low side converter is controlled as step up. At a given instant of time, only one
converter is controlled and other acts as diode bridge converter. The proposed system is
characterized by good dynamic properties and high efficiency because of low switching losses.
Using the same power components for achieving bidirectional flow of power in the symmetrical
circuit topology provides a simple, efficient and galvanic ally isolated that is especially attractive for
use in battery charging/discharging circuits.High frequency isolation transformer plays an important
role in achieving galvanic isolation and also for reducing the system size, weight and cost. Power
MOSFET switches, provided with snubber circuit and PI filter at the output side are employed to
reduce the ripple and for voltage regulation in this proposed thesis.
International Journal of Engineering Research and Development (IJERD)IJERD Editor
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
yahoo journals, bing journals, International Journal of Engineering Research and Development, google journals, hard copy of journal
Push-Pull Converter Fed Three-Phase Inverter for Residential and Motor LoadIJPEDS-IAES
The proposed paper is an new approach for power conditioning of a PV
(photo-voltaic) cell array. The main objective is to investigate an approach to
provide and improve the delivered electric energy by means of power
conditioning structures with the use of alternative renewable resources
(ARRs) for remote rural residential or industrial non-linear loads. This
approach employs a series-combined connected boost and buck boost DCDC
converter for power conditioning of the dc voltage provided by a photovoltaic
array. The input voltage to the combined converters is 100 V
provided from two series connected PV cells, which is converted and
increased to 200 V at the dc output voltage. Series-combined connected
boost and buck-boost DC-DC converters operate alternatively. This helps to
reduce the input ripple current and provide the required 400 Vdc on a
sinusoidal PWM three-phase inverter. Analysis of the two series-combined
DC-DC converters is presented along with simulation results. Simulations of
the series-combined DC-DC converters are presented with an output DC
voltage of 200 V and a maximum output load of Po=600 W.
Real Time Implementation of Variable Step Size Based P&O MPPT for PV Systems ...IJPEDS-IAES
Nowadays Solar energy is an important energy source due to the energy crisis and environment pollution. Maximum power point tracking (MPPT) algorithm improves the utilization efficiency of a photovoltaic systems. In this paper an improved P&O MPPT algorithm is developed and simulated using MATLAB / SIMULINK to control the DC/DC buck converter. The obtained simulink model is also verified using dspace tool. Both the simulated and experimental results are validated by also comparing them with conventional MPPT methods. The performance measures show the increase in the efficiency of PV system by the proposed model.
High gain dc-dc step up converters have been used in renewable energy systems, for example, photovoltaic grid connected system and fuel cell power plant to step up the low level dc voltage to a high level dc bus voltage. If the conventional boost converter is to meet this demand, it should be operated at an extreme duty cycle (duty cycle closes to unity), which will cause electromagnetic interference, reverse recovery problem and conduction loss at the power switches. This paper proposes a class of non-isolated dc-dc step up converters which provide very high voltage gain at a small duty cycle (duty cycle < 0.5). Firstly, the converter topologies are derived based on active switched inductor network and combination of active and passive switched inductor networks; secondly, the modes of operation of proposed active switched inductor converter and combined active and passive switched inductor converter are illustrated; thirdly, the performance of the proposed converters are analyzed mathematically in details and compared with conventional boost converter. Finally, the analysis is verified by simulation results.
High Proficiency Grid ConnectedPhotovoltaic Power Generation SystemIJRES Journal
Solar energy hasbecomepopular nowadays and desire for clean energy. Since the solar radiation on no occasion remains constant,it keeps on insecure throughout the day. The need of the hour is to distribute a constant voltage to the grid irrespective of the deviation in temperatures and solar insolation. The inverter is designed from a boost converter along with a line frequency. The voltage from the boost converter is fedto the grid through inverter. In this proposed method high efficiency can be achievedby using only one switch functioning at high frequency at a time. The converter uses IGBT and ultra-fast reverse recovery diode. The simulation and experiment results are verified using MATLAB/Simulink software.
Z - Source Multi Level Inverter Based PV Generation SystemIJERA Editor
In this paper a novel technique of Z-Source multilevel Inverter based PV Generation system is implemented and simulated using MATLAB-Simulink simulation software. The Photovoltaic cells are healthier option for converting solar energy into electricity. Due to high capital cost and low efficiency PV cells have not yet been a fully smart choice for electricity users. To enhance the performance of the system, Z-Source multi level inverter can be used in place of conventional Voltage Source Inverter (VSI) in Solar Power Generation System. The PV cell model is developed using circuit mathematical equations. The Z-Source multilevel inverter is modeled to realize boosted DC to AC conversion (inversion) with low THD. Outcome shows that the energy conversion efficiency of ZSMLI is a lot improved as compared to conventional voltage Source Inverter (VSI). By doing FFT analysis we can know the total THD.
In this paper a buck-boost dc-dc converter for pv application is proposed, which is mainly composed of a buck – boost converter, PV panel, load and a battery. Existing dc-dc converter can convert the power from the PV panel, but unfortunately the PV panel can only provide power when there is a high intensity of light. In order to provide power supply to the load without any interruption, buck-boost dc-dc converter is introduced. The power intermittency issue of PV panel can be overcome with the aid of a secondary supply which is in this case, the batter. The integration system between the primary and the secondary supply is controlled by a simple proposed control scheme. Battery act as a power in the low voltage side while PV panel is taking over in the high voltage side. Buck-boost converter is operated either is buck or boost mode according to the performance of the PV panel. This paper is presented the simple control scheme to decide the mode suitable for the buck and boost mode. Various conditions are simulated to verify the working operation of the buck-boost converter and to representing solar panel in real life. Simulation and experimental are carried out to verify the system.
Performance enhancement of DC/DC converters for solar powered EV IJECEIAES
The paper initially presents the essential drive arrangement required for electric vehicle. It requests high power bidirectional stream ability, with wide info voltage range, and yield voltage of vitality stockpiling gadgets, for example, super capacitors or batteries shift with the adjustment in stack. At that point the tenacity and outline of previously mentioned converter is proposed in this paper. The converter which relates a half extension topology, has high power stream ability and least gadget focuses on that can appropriately interface a super capacitor with the drive prepare of a crossover electric vehicle. Besides, by contrasting the fundamental qualities and applications with some ordinary bidirectional DC/DC converter, the proposed converter has low gadget rating and can be controlled by obligation cycle and stage move. Finally, the most essential attributes of this converter is that it utilizes the transformer spillage inductance as the essential vitality exchange component and control parameters, Simulation waveforms in light of MATLAB recreation are given to exhibit the integrity of this novel topology, and this converter is additionally reasonable for high power application, specifically to control the charge-release of super capacitors or batteries that can be utilized as a part of cross breed solar based electric vehicle.
Research Inventy : International Journal of Engineering and Scienceinventy
Research Inventy : International Journal of Engineering and Science
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed
Hysteresis SVM for Coupled Inductor Z Source Diode Clamped 3-Level Inverter B...IAES-IJPEDS
Due to its advantages such as it can defeat problems such as leakage current
and insertion of DC in the grid and provides low stress on power devices,
Diode-clamped three-level inverter (DCTLI) is habitually used in
transformerless photovoltaic (PV) connected to grid network. But it still has
a problem of shoot-through which dwells in its legs, so its operation not
reliable. Z source network is employed to permit operation without shoot
through risk and improve its reliability. Coupled inductors are replaced the
line transformers in to attain lower cost, reduced size, and improved its
reliability and efficiency. Coupled inductor which avoids leakage current
problem and losses. It employs coupled inductor z source diode clamped
three level inverter (CI-Z-DC-TLI) to boost the voltage and further progress
the consistency of the proposed system by avoiding the shoot through the
problem. The proposed system assures that common-mode voltage
and shoot-through risk is avoided. Moreover, controlling DC-TLI with
Hysteresis SVM algorithm which improves output voltage and current
control. Simulation and experimental results of this proposed system were
analyzed using MATLAB environment and FPGA hardware.
Analysis and Design of Solar Photo voltaic Grid Connected Inverterijeei-iaes
This paper presents common mode voltage analysis of single phase grid connected photovoltaic inverter. Many researchers proposed different grid tie inverters for applications like domestic powering, street lighting, water pumping, cooling and heating applications, however traditional grid tie PV inverter uses either a line frequency or a high frequency transformer between the inverter and grid but losses will increase in the network leading to reduced efficiency of the system. In order to increase the efficiency, with reduced size and cost of the system, the effective solution is to remove the isolation transformer. But common mode (CM) ground leakage current due to parasitic capacitance between the PV panels and the ground making the system unreliable. The common mode current reduces the efficiency of power conversion stage, affects the quality of grid current, deteriorate the electric magnetic compatibility and give rise to the safety threats. In order to eliminate the common mode leakage current in Transformerless PV systm two control algorithms of multi-carrier pwm are implemented and compared for performance analysis.The shoot-through issue that is encountered by traditional voltage source inverter is analyzed for enhanced system reliability. These control algorithms are compared for common mode voltage and THD comparisons. The proposed system is designed using MATLAB/SIMULINK software for analysis.
Performance numerical evaluation of modified single-ended primary-inductor c...IJECEIAES
Single-ended primary-inductor converter (SEPIC) was considered a good alternative to a DC-DC converter for photovoltaic (PV) systems. The SEPIC converter can operate with an input voltage greater or less than the regulated output voltage, or as a step-up or step-down. As a step-up converter, SEPIC boosts PV voltage to specific levels. However, gain limitation and voltage stress continue to reduce the efficiency of conventional SEPIC converters. Because of this, researchers created a modified SEPIC converter to improve performance. In this paper, six modified SEPIC converters were compared and evaluated. To compare fairly, all modified SEPIC converters are nonisolated and use a single switch. Power simulator (PSIM) software was used to simulate each converter with a BISOL BMO-250 PV module and maximum power point tracking (MPPT) P&O controller. The converter with the highest static voltage gain and lowest duty cycle has been identified. It results in up to ten times voltage increment with a 0.8-duty ratio. All topologies have the same voltage stress, with maximum and minimum values of 30.1 and 29.5 V, respectively. On the other hand, each topology produces different average efficiencies, with the highest and lowest efficiency at 99.5% and 97.2%, respectively.
Fuzzy based control of Transformer less Coupled inductor based DC-DC converterIJERA Editor
Most of the industrial applications use any one of the basic DC-DC converter configurations namely buck,
boost, buck–boost, and Cuk converters. These converters are non-isolating converters. Buck-boost converters
use inductors for storing energy from the source and release the same to load or output. This results in high
stress across magnetic components. This drawback restricts usage of buck-boost converters to low power
applications. Flyback converters popularly have known as buck-boost converters uses transformers for
achieving wide range of step down and step up voltages. Coupled inductor based converters or tapped inductor
based converters are used for achieving wide input – wide output conversion ratios. Coherent transition between
step-down and step-up modes is achieved by a proper control scheme. This paper proposes fuzzy logic based
closed loop control scheme for control of converter switches. Theoretical derivations of control parameters with
their membership values, mamdani based rules for development of fuzzy rules and simulation results of a
coupled inductor based DC-DC converter using MATLAB / SIMULINK are concluded.
Design and implementation a novel single switch high gain DC-DC converter ba...IJECEIAES
A novel high-gain and high-efficiency direct current to direct current
(DC-DC) converter is introduced in this paper. The presented converter is suitable for low-voltage renewable energy resources such as photovoltaic (PV) and fuel cell (FC). The existence of series inductance with the input source ensures continuous and low-ramp input current, which is important for extracting maximum power from resources. Using coupled inductor technology and an intermediate capacitor in the suggested converter leads to a high gain voltage. In the presented topology for recovering energy from the leakage inductor, reducing voltage stress on the power switch, and so decreasing overall converter losses, a passive clamp circuit is used. The suitable operation range of duty cycle in the converter, besides the leakage inductor, decreases the problem of reverse recovery in diodes. The low value of the leakage inductor and the low volume and cost of the proposed converter are due to the low turn ratio of the coupled inductor. Details of the operation principles of the proposed converter have been discussed in this paper. The presented simulation and laboratory prototype results verify the theoretical analysis and performance of the suggested topology.
A Power quality problem is an occurrence of nonstandard voltage, current or frequency that results in a
failure or a misoperation of end user equipments. Utility distribution networks, sensitive industrial loads and
critical commercial operations suffer from various types of outages and service interruptions which can cost
significant financial losses. With the increase in load demand, the Renewable Energy Sources (RES) are
increasingly connected in the distribution systems which utilizes power electronic Converters/Inverters. This
paper presents a single-stage, three-phase grid connected solar photovoltaic (SPV) system. The proposed system
is dual purpose, as it not only feeds extracted solar energy into the grid but it also helps in improving power
quality in the distribution system. The presented system serves the purpose of maximum power point tracking
(MPPT), feeding SPV energy to the grid, harmonics mitigation of loads connected at point of common coupling
(PCC) and balancing the grid currents. The SPV system uses a three-phase voltage source converter (VSC) for
performing all these functions. An improved linear sinusoidal tracer (ILST)-based control algorithm is proposed
for control of VSC. In the proposed system, a variable dc link voltage is used for MPPT. An instantaneous
compensation technique is used incorporating changes in PV power for fast dynamic response. The SPV system
is first simulated in MATLAB along with Simulink and simpower system toolboxes.
This paper presents the detail circuitry modeling of single phase off-grid inverter for small standalone system applications. The entire model is developed in MATLAB/Simulink platform using circuitry model. This off grid inverter consists of a high frequency DC-DC step up converter cascaded with a full bridge PI control voltage source inverter using SPWM modulation with LC filter to produce sine wave output. This is a common design used in many small commercial off-grid inverter. This off-grid inverter model is capable to produce AC sinewave output voltage at 230 V 50 Hz up to 1 kW power from a 48 V DC lead acid battery source. The AC sine wave output waveform achieved a voltage Total Harmonic Distortion (THD) of less than 1 % which is almost a pure sine wave. The conversion efficiency performance of the off-grid inverter achieved more than 94 %. The performance of the model is validated by real commercial off-grid inverter. The performance validation experiment shows that the off-grid inverter Simulink model conversion efficiency and THD performance are comparable to the commercial off-grid inverter. This model contributes to assist small to medium standalone system load and battery sizing design with greater accuracy.
Application of Distribution Power Electronic Transformer for Medium VoltageIAES-IJPEDS
In this paper a distribution power electronic transformer (DPET) for feeding critical loads is presented. The PE based transformer is a multi-port converter that can connect to medium voltage levels on the primary side. Bidirectional power flow is provided to the each module. The presented structure consists of three stages: an input stage, an isolation stage, and an output stage. The input current is sinusoidal, and it converts the high AC input voltage to low DC voltages. The isolated DC/DC converters are then connected to the DC links and provide galvanic isolation between the HV and LV sides. Finally, a three-phase inverter generates the AC output with the desired amplitude and frequency. The proposed DPET is extremely modular and can be extended for different voltage and power levels. It performs typical functions and has advantages such as power factor correction, elimination of voltage sag and swell, and reduction of voltage flicker in load side. Also in comparison to conventional transformers, it has lower weight, lower volume and eliminates necessity for toxic dielectric coolants the DPET performance is verified in MATLAB simulation.
Hardware Implementation of Solar Based Boost to SEPIC Converter Fed Nine Leve...IJPEDS-IAES
Multi level inverters are widely used in high power applications because of
low harmonic distortion. This paper deals with the simulation
and implementation of PV based boost to SEPIC converter with multilevel
inverter. The output of PV system is stepped up using boost to sepic
converter and it is converted into AC using a multilevel inverter.
The simulation and experimental results with the R load is presented in this
paper. The FFT analysis is done and the THD values are compared. Boost to
SEPIC converter is proposed to step up the voltage to the required value. The
experimental results are compared with the simulation results. The results
indicate that nine level inverter system has better performance than seven
level inverter system.
This paper presents the simulation design of dc/dc interleaved boost converter with zero-voltage switching (ZVS). By employin the interleaved structure, the input current stresses to switching devices were reduced and this signified to a switching conduction loss reduction. All the parameters had been calculated theoretically. The proposed converter circuit was simulated by using MATLAB/Simulink and PSpice software programmes. The converter circuit model, with specifications of output power of 200 W, input voltage range from 10~60 V, and operates at 100 kHz switching frequency was simulated to validate the designed parameters. The results showed that the main switches of the model converter circuit achieved ZVS conditions during the interleaving operation. Consequently, the switching losses in the main switching devices were reduced. Thus, the proposed converter circuit model offers advantages of input current stress and switching loss reductions. Hence, based on the designed parameters and results, the converter model can be extended for hardware implementation.
Universal demand for power increases due to continuous development to fulfil all these demand. Resources
are used with optimization. A high efficiency and high power factor converters are the major parts of energy
transfer system. This paper present a general review on single stage forward and flyback converter topologies to get
better its performance. This is paper presents a kind general idea of increasing efficiency and power factor of single
stage forward and fly back converter.
Development and implementation of two-stage boost converter for single-phase ...IJECEIAES
This paper offers a two-stage boost converter for a single-phase inverter without transformer for PV systems. Each stage of the converter is separately controlled by a pulse width modulated signal. A Simulink model of the converter using efficient voltage control topology is developed. The proposed circuit performance characteristics are explained and the obtained simulation results are confirmed through the applied experiments. Moreover, this paper has examined the control circuit of a single-phase inverter that delivers a pure sine wave with an output voltage that has the identical value and frequency as a grid voltage. A microcontroller supported an innovative technology is utilized to come up with a sine wave with fewer harmonics, much less price and an easier outline. A sinusoidal pulse width modulation (SPWM) technique is used by a microcontroller. The developed inverter integrated with the twostage boost converter has improved the output waveform quality and controlled the dead time as it decreased to 63 µs compared to 180 µs in conventional methods. The system design is reproduced in Proteus and PSIM Software to analyze its operation principle that is confirmed practically.
A Integrated Technique of SIDO PFC Fly back Converter in power systemIJMTST Journal
Energy saving is the major international efforts to control down the global warming .Power electronics based devices has being improving day by day for saving the electrical energy in the power grids. The govt. of India is also contributing several projects based on energy conservation. The Designing of a single-inductor dual output (SIDO) fly-back power factor correction (PFC) converter is proposed, in which the PFC and power conversion are done at the same time, multiplexing of a single-inductor is implemented through which each output can be regulated independently. The converter will be operating under in critical conduction mode (CRM). A SIDO PFC converter is a system of dual efficient DC output obtained from the AC source, it can also be replaced by solar panel and our system is capable of running a dc motor also, fly back converter can be used in both ac-dc and dc-dc conversion process. The efficiency along with power factor, total harmonic distortion (THD), settling time and output accuracy of this converter will be improved by implementing the neural network as controllers in the system
Implementation of a Voltage Multiplier based on High Step-up Converter using FLCIJMTST Journal
A Front end of the Photovoltaic Solar Panel is been proposed based on Step-Up Converter. The use of
distributed energy resources is increasingly being pursued as a supplement and an alternative to large
conventional central power stations. The specification of a power electronic interface is subject to
requirements related not only to the renewable energy source itself but also to its effects on the power-system
operation, especially where the intermittent energy source constitutes a significant part of the total system
capacity. Implementing a voltage multiplier module, an asymmetrical interleaved high step-up converter
obtains high step-up gain without operating at an extreme duty ratio. The voltage multiplier module is
composed of a conventional boost converter and coupled inductors. An extra conventional boost converter is
integrated into the first phase to achieve a considerably higher voltage conversion ratio. The two-phase
configuration not only reduces the current stress through each power switch, but also constrains the input
current ripple, which decreases the conduction losses of metal–oxide–semiconductor field-effect transistors.
In addition, the proposed converter functions as an active clamp circuit, which alleviates large voltage spikes
across the power switches. Finally, the simulation circuitry with a 40V input voltage and 230V output voltage
is operated to verify its performance analysis with respect to the Fuzzy Logic Controller. The highest
efficiency is 97.75%.
Renewable Energy Based on Current Fed Switched Inverter for Smart Grid Applic...MangaiK4
Abstract - Renewable energy is used in the current fed switched inverter for high power production. High voltage support, wide yield ranges of operation, shoot-through resistance are a portion of the desired properties of an inverter for a reliable, versatile and less ripple AC inversion. This paper proposes a single stage, high boost inverter with buck-boost capacity which has a few particular advantages over traditional voltage source inverters (VSI) like better EMI noise, wide input and output voltage range of operation, and so on. The proposed inverter is named as Current-Fed Switched Inverter (CFSI). A renewable energy based converter structure of CFSI has been created which supplies both AC and DC loads, at the same time, from a single DC supply which makes it reasonable for DC smart grid application. This paper proposes the operation and control of a CFSI based converter which directs the AC and DC conversion voltages at their reference. The advancement of the proposed converter from essential current fed DC/DC topology is explained. The closed loop controller is verified by using the MATLAB/ Simulink environment.
DESIGN AND SIMULATION ANALYSIS OF SEVEN LEVEL CASCADED GRID CONNECTED INVERTE...ijiert bestjournal
This paper presents the simulation analysis of sev en level cascaded grid connected inverter and also compared with five level inverter for %THD for voltage and current by using level shifted PWM techniques. The proposed system are modeled and simulated through computer software tool using MATLAB /SIMULINK. This paper also presen ts the design and development of the seven level cascaded grid connected inverter.The LC filter is also use in the output side to further reduce the THD values.Seven level inverter is utili se as a power converter to inject power generated from pv source to the grid.Multilevel inv erters have been mainly used in medium- or high-power system applications,such as static reac tive power compensation and adjustable-speed drives. In these applications,due to the limitatio ns of the currently available power semiconductor technology.The term multilevel began with the three-level converter. Subsequently,several multilevel converter topologi es have been developed. However,the elementary concept of a multilevel converter to ach ieve higher power is to use a series of power semiconductor switches with several lowerVoltage dc sources to perform the power conversion by synthesizing a staircase voltage waveform. Capac itors,batteries,and renewable energy voltage sources can be used as the multiple dc volt age sources. The commutation of the power switches aggregate these multiple dc sources in ord er to achieve high voltage at the output;however,the rated voltage of the power semiconduct or switches depends only upon the rating of the dc voltage sources to which they are connected Percentage of THD for R,RL,RLC load taken and simulation results analyse and studied an d comparison made between five level and seven level .
Similar to Basic MOSFET Based vs Couple-Coils Boost Converters for Photovoltaic Generators (20)
Inter-Area Oscillation Damping using an STATCOM Based Hybrid Shunt Compensati...IJPEDS-IAES
FACTS devices are one of the latest technologies which have been used to
improve power system dynamic and stability during recent years. However,
widespread adoption of this technology has been hampered by high cost
and reliability concerns. In this paper an economical phase imbalanced shunt
reactive compensation concept has been introduced and its ability for power
system dynamic enhancement and inter-area oscillation damping are
investigated. A hybrid phase imbalanced scheme is a shunt capacitive
compensation scheme, where two phases are compensated by fixed shunt
capacitor (C) and the third phase is compensated by a Static Synchronous
Compensator (STATCOM) in shunt with a fixed capacitor (CC). The power
system dynamic stability enhancement would be achieved by adding
a conventional Wide Area Damping Controller (WADC) to the main control
loop of the single phase STATCOM. Two different control methodologies
are proposed: a non-optimized conventional damping controller
and a conventional damping controller with optomised parameters that are
added to the main control loop of the unbalanced compensator in order to
damp the inter area oscillations. The proposed arrangement would, certainly,
be economically attractive when compared with a full three-phase
STATCOM. The proposed scheme is prosperously applied in a 13-bus
six-machine test system and various case studies are conducted to
demonstrate its ability in damping inter-area oscillations and power system
dynamic enhancement.
Fuzzy Gain-Scheduling Proportional–Integral Control for Improving the Speed B...IJPEDS-IAES
In this article, we have set up a vector control law of induction machine
where we tried different type of speed controllers. Our control strategy is of
type Field Orientated Control (FOC). In this structure we designed a Fuzzy
Gain-Scheduling Proportional–Integral (Pi) controller to obtain best result
regarding the speed of induction machine. At the beginning we designed a Pi
controller with fixed parameters. We came up to these parameters by
identifying the transfer function of this controller to that of Broïda (second
order transfer function). Then we designed a fuzzy logic (FL) controller.
Based on simulation results, we highlight the performances of each
controller. To improve the speed behaviour of the induction machine, we
have designend a controller called “Fuzzy Gain-Scheduling Proportional–
Integral controller” (FGS-PI controller) which inherited the pros of the
aforementioned controllers. The simulation result of this controller will
strengthen its performances.
Advance Technology in Application of Four Leg Inverters to UPQCIJPEDS-IAES
This article presents a novel application of four leg inverter with
conventional Sinusoidal Pulse Width Modulation (SPWM) Scheme to
Unified Power Quality Conditioner (UPQC). The Power Quality problem
became burning issues since the starting of high voltage AC transmission
system. Hence, in this article it has been discussed to mitigate the PQ issues
in high voltage AC systems through a three phase Unified Power Quality
Conditioner (UPQC) under various conditions, such as harmonic mitigation
scheme, non linear loads, sag and swell conditions as well. Also, it proposes
to control harmoincs with various artificial intelligent techniques. Thus
application of these control technique such as Neural Networks (ANN)
Fuzzy Logic makes the system performance in par with the standards
and also compared with existing system. The simulation results based on
MATLAB/Simulink are discussed in detail to support the concept developed
in the paper.
Modified SVPWM Algorithm for 3-Level Inverter Fed DTC Induction Motor DriveIJPEDS-IAES
In this paper, a modified space vector pulse width modulation (MSVPWM)
algorithm is developed for 3-level inverter fed direct torque controlled
induction motor drive (DTC-IMD). MSVPWM algorithm simplifies
conventional space vector pulse width modulation (CSVPWM) algorithm for
multilevel inverter (MLI), whose complexity lies in sector/subsector/subsubsector
identification; which will commensurate with number of levels. In
the proposed algorithm sectors are identified as in two level inverter
and subsectors/sub-subsectors are identified by shifting the original reference
vector to sector 1 (S1). This is valid due to the fact that a three level space
vector plane is a composition of six two level space planes, and are
symmetrical with reference to six pivot states. Switching state/sequence
selection is also very important while dealing with SVPWM strategy for
MLI. In the proposed algorithm out of 27 available switching states apt
switching state is selected based on sector and subsector number, such that
voltage ripple is considerably less. To validate the proposed algorithm, it is
tested on a three level neutral point clamped (NPC) inverter fed DTC-IMD.
The performance of the MSVPWM algorithm is analyzed by comparing no
load stator current ripple of the three level DTC-IMD with two level
DTC-IMD. Significant reduction in steady state torque and flux ripple is
observed. Hence, reduced acoustic noise is a distinctive facet of the proposed
method.
Modelling of a 3-Phase Induction Motor under Open-Phase Fault Using Matlab/Si...IJPEDS-IAES
The d-q model of Induction Motors (IMs) has been effectively used as an
efficient method to analyze the performance of the induction machines. This
study presents a step by step Matlab/Simulink implementation
of a star-connected 3-phase IM under open-phase fault (faulty 3-phase IM)
using d-q model. The presented technique in this paper can be simply
implemented in one block and can be made available for control purposes.
The simulated results provide to show the behavior of the star-connected 3-phase IM under open-phase fault condition.
Performance Characteristics of Induction Motor with FielIJPEDS-IAES
With development of power electronics and control Theories, the AC motor
control becomes easier. So the AC motors are used instead of the DC motor
in the drive applications. With this development, a several methods of control
are invented. The field oriented control and direct torque control are from the
best methods to control the drive systems. This paper is compared between
the field oriented control and direct torque control to show the advantages
and disadvantages of these methods of controls. This study discussed the
effects of these methods of control on the total harmonic distortion of the
current and torque ripples. This occurs through study the performance
characteristics of the AC motor. The motor used in this study is an induction
motor. This study is simulated through the MATLAB program.
A Novel Modified Turn-on Angle Control Scheme for Torque- Ripple Reduction in...IJPEDS-IAES
In recent years, Switched Reluctance Motors (SRM) have been dramatically
considered with both researchers and industries. SRMs not only have a
simple and reliable structure, but also have low cost production process.
However, discrete torque production of SRM along with intensive magnetic
saturation in stator and rotor cores are the major drawbacks of utilizing in
variety of industrial applications and also causes the inappropriate torque
ripples. In this paper, a modified logical-rule-based Torque Sharing Function
(TSF) method is proposed considering turn-on angle control. The optimized
turn-on angle for conducting each phase is achieved by estimating the
inductance curve in the vicinity of unaligned position and based on an
analytical solution for each phase voltage equation. Simulation results on a
four-phase switched reluctance motor and comparison with the conventional
methods validates the effectiveness of the proposed method.
Modeling and Simulation of Induction Motor based on Finite Element AnalysisIJPEDS-IAES
This paper presents the development of a co-simulation platform of induction
motor (IM). For the simulation, a coupled model is introduced which
contains the control, the power electronics and also the induction machine.
Each of these components is simulated in different software environments.
So, this study provides an advanced modeling and simulation tools for IM
which integrate all the components into one common simulation platform
environment. In this work, the IM is created using Ansys-Maxwell based on
Finite Element Analysis (FEA), whereas the power electronic converter is
developed in Ansys-Simplorer and the control scheme is build in MATLABSimulink
environment. Such structure can be useful for accurate design
and allows coupling analysis for more realistic simulation. This platform is
exploited to analyze the system models with faults caused by failures of
different drive’s components. Here, two studies cases are presented: the first
is the effects of a faulty device of the PWM inverter, and the second case is
the influence of the short circuit of two stator phases. In order to study the
performance of the control drive of the IM under fault conditions,
a co-simulation of the global dynamic model has been proposed to analyze
the IM behavior and control drives. In this work, the co-simulation has been
performed; furthermore the simulation results of scalar control allowed
verifying the precision of the proposed FEM platform.
Comparative Performance Study for Closed Loop Operation of an Adjustable Spee...IJPEDS-IAES
In this paper an extensive comparative study is carried out between PI
and PID controlled closed loop model of an adjustable speed Permanent
Magnet Synchronous Motor (PMSM) drive. The incorporation of Sinusoidal
Pulse Width Modulation (SPWM) strategy establishes near sinusoidal
armature phase currents and comparatively less torque ripples without
sacrificing torque/weight ratio. In this closed loop model of PMSM drive, the
information about reference speed is provided to a speed controller, to ensure
that actual drive speed tracks the reference speed with ideally zero steady
state speed error. The entire model of PMSM closed loop drive is divided
into two loops, inner loop current and outer loop speed. By taking the
different combinations of two classical controllers (PI & PID) related with
two loop control structure, different approximations are carried out. Hence a
typical comparative study is introduced to familiar with the different
performance indices of the system corresponding to time domain and
frequency domain specifications. Therefore overall performance of closed
loop PMSM drive is tested and effectiveness of controllers will be
determined for different combinations.
Novel Discrete Components Based Speed Controller for Induction MotorIJPEDS-IAES
This paper presents an electronic design based on general purpose discrete
components for speed control of a single phase induction motor drive. The
MOSFETs inverter switching is controlled using Sampled Sinusoidal Pulse
Width Modulation (SPWM) techniques with V/F method based on Voltage
Controlled Oscillator (VCO). The load power is also controlled by a novel
design to produce a suitable SPWM pulse. The proposed electronic system
has ability to control the output frequency with flexible setting of lower limit
to less than 1 Hz and to higher frequency limits to 55 Hz. Moreover, the
proposed controller able to control the value of load voltage to frequency
ratio, which plays a major parameter in the function of IM speed control.
Furthermore, the designed system is characterized by easy manufacturing
and maintenance, high speed response, low cost, and does not need to
program steps as compared to other systems based on Microcontroller
and digital signal processor (DSP) units. The complete proposed electronic
design is made by the software of NI Multisim version 11.0 and all the
internal sub-designs are shown in this paper. Simulation results show the
effectiveness of electronic design for a promising of a high performance IM
PWM drive.
Sensorless Control of a Fault Tolerant PMSM Drives in Case of Single-Phase Op...IJPEDS-IAES
This paper introduces a sensorless-speed-controlled PMSM motor fed by a
four-leg inverter in case of a single phase open circuit fault regardless in
which phase is the fault. To minimize the system performance degradation
due to a single phase open circuit fault, a fault tolerant control strategy that
includes taking appropriate actions to control the two remaining healthy
currents is used in addition to use the fourth leg of the inverter. Tracking the
saliency is done through measuring the dynamic current responses of the
healthy phases of the PMSM motor due the IGBT switching actions using the
fundamental PWM method without introducing any modification to the
operation of the fourth leg of the inverter. Simulation results are provided to
verify the effectiveness of the proposed strategy for sensorless controlling of
a PMSM motor driven by a fault-tolerant four-phase inverter over a wide
speed ranges under the case of a single phase open circuit.
Improved Stator Flux Estimation for Direct Torque Control of Induction Motor ...IJPEDS-IAES
Stator flux estimation using voltage model is basically the integration of the
induced stator back electromotive force (emf) signal. In practical
implementation the pure integration is replaced by a low pass filter to avoid
the DC drift and saturation problems at the integrator output because of the
initial condition error and the inevitable DC components in the back emf
signal. However, the low pass filter introduces errors in the estimated stator
flux which are significant at frequencies near or lower than the cutoff
frequency. Also the DC components in the back emf signal are amplified at
the low pass filter output by a factor equals to . Therefore, different
integration algorithms have been proposed to improve the stator flux
estimation at steady state and transient conditions. In this paper a new
algorithm for stator flux estimation is proposed for direct torque control
(DTC) of induction motor drives. The proposed algorithm is composed of a
second order high pass filter and an integrator which can effectively
eliminates the effect of the error initial condition and the DC components.
The amplitude and phase errors compensation algorithm is selected such that
the steady state frequency response amplitude and phase angle are equivalent
to that of the pure integrator and the multiplication and division by stator
frequency are avoided. Also the cutoff frequency selection is improved; even
small value can filter out the DC components in the back emf signal. The
simulation results show the improved performance of the induction motor
direct torque control drive with the proposed stator flux estimation algorithm.
The simulation results are verified by the experimental results.
Minimization of Starting Energy Loss of Three Phase Induction Motors Based on...IJPEDS-IAES
The purpose of this paper is to minimize energy losses consumed by three
phase induction motors during starting with wide range of load torque from
no load to full load. This will limit the temperature rise and allows for more
numbers of starting during a definite time. Starting energy losses
minimization is achieved by controlling the rate of increasing voltage
and frequency to start induction motor under certain load torque within a
definite starting time. Optimal voltage and frequency are obtained by particle
swarm optimization (PSO) tool according to load torque. Then, outputs of the
PSO are used to design a neuro-fuzzy controller to control the output voltage
and frequency of the inverter during starting for each load torque. The
starting characteristics using proposed method are compared to that of direct
on line and V/F methods. A complete model of the system is developed using
SIMULINK/MATLAB.
Transformer Less Voltage Quadrupler Based DC-DC Converter with Coupled Induct...IJPEDS-IAES
In this paper a voltage quadrupler dc-dc converter with coupled inductor
and π filter is presented. The use of the coupled inductor reduces the high
leakage inductance which is present in a transformer enabled converter.
The output ripples in the converter is reduced by providing a π filter.
The interleaved voltage quadrupler is used in this system in order to boost the
output voltage. The voltage multiplier improves the output voltage gain.
The main advantage of this system is more voltage gain when compared with
the transformer eneabled circuit and the overall efficiency of the system is
improved. The circuit is simple to control. As a final point of this research,
the simulation and the hardware investigational results are presented to
demonstrate the effectiveness of this proposed converter.
IRAMY Inverter Control for Solar Electric VehicleIJPEDS-IAES
Solar Electric Vehicles (SEV) are considered the future vehicles to solve the issues of air pollution, global warming, and the rapid decreases of the petroleum resources facing the current transportation technology. However, SEV are still facing important technical obstacles to overcome. They include batteries energy storage capacity, charging times, efficiency of the solar panels and electrical propulsion systems. Solving any of those problems and electric vehicles will compete-complement the internal combustion engines vehicles. In the present work, we propose an electrical propulsion system based on three phase induction motor in order to obtain the desired speed and torque with less power loss. Because of the need to lightweight nature, small volume, low cost, less maintenance and high efficiency system, a three phase squirrel cage induction motor (IM) is selected in the electrical propulsion system. The IM is fed from three phase inverter operated by a constant V/F control method and Space Vector Pulse Width Modulation (SVPWM) algorithm. The proposed control strategy has been implemented on the texas instruments TM320F2812 Digital Signal Processor (DSP) to generate SVPWM signal needed to trigger the gates of IGBT based inverter. The inverter used in this work is a three phase inverter IRAMY20UP60B type. The experimental results show the ability of the proposed control strategy to generate a three-phase sine wave signal with desired frequency. The proposed control strategy is experimented on a locally manufactured EV prototype. The results show that the EV prototype can be propelled to speed up to 60km/h under different road conditions.
Design and Implementation of Single Phase AC-DC Buck-Boost Converter for Powe...IJPEDS-IAES
This paper discusses the Power Factor Correction (PFC) for single phase AC-DC Buck-Boost Converter (BBC) operated in Continuous Conduction Mode (CCM) using inductor average current mode control. The proposed control technique employs Proportional-Integral (PI) controller in the outer voltage loop and the Inductor Average Current Mode Control (IACMC) in the inner current loop for PFC BBC. The IACMC has advantages such as robustness when there are large variations in line voltage and output load. The PI controller is developed by using state space average model of BBC. The simulation of the proposed system with its control circuit is implemented in MatLab/Simulink. The simulation results show a nearly unity power factor can be attained and there is almost no change in power factor when the line frequency is at various ranges. Experimental results are provided to show its validity and feasibility.
Improvement of Wind farm with PMSG using STATCOMIJPEDS-IAES
This paper studies about the dynamic performance of the Permanent Magnet Synchronous Generator with Static Synchronous Compensator (STATCOM) for Wind farm integration. A whole dynamic model of wind energy conversion system (WECS) with PMSG and STATCOM are established in a MATLAB environment. With this model the dynamic behaviour of the generator and the overall system has been studied to determine the performance of them with and without STATCOM. Final results portrays that the WECS based PMSG with STATCOM improves the transient response of the wind farm when the system is in fault.
Modeling and Control of a Doubly-Fed Induction Generator for Wind Turbine-Gen...IJPEDS-IAES
This paper presents a vector control direct (FOC) of double fed induction generator intended to control the generated stator powers. This device is intended to be implemented in a variable-speed wind-energy conversion system connected to the grid. In order to control the active and reactive power exchanged between the machine stator and the grid, the rotor is fed by a bi-directional converter. The DFIG is controlled by standard relay controllers. Details of the control strategy and system simulation were performed using Simulink and the results are presented in this here to show the effectiveness of the proposed control strategy.
A Review on Design and Development of high Reliable Hybrid Energy Systems wit...IJPEDS-IAES
Hybrid Energy system is a combination of two or more different types of energy resources. Now a day this hybrid energy system plays key role in various remote area power applications. Hybrid energy system is more reliable than single energy system. This paper deals with high reliable hybrid energy system with solar, wind and micro hydro resources. The proposed hybrid system cable of multi mode operation and high reliable due to non communicated based controllers (Droop Characteristic Control) are used for optimal power sharing. Size of battery can be reduced because hydro used as back up source and Maximum power point Tracking also applied to solar and wind energy systems.
Fuzzy Sliding Mode Control for Photovoltaic SystemIJPEDS-IAES
In this study, a fuzzy sliding mode control (FSMC) based maximum power point tracking strategy has been applied for photovoltaic (PV) system. The key idea of the proposed technique is to combine the performances of the fuzzy logic and the sliding mode control in order to improve the generated power for a given set of climatic conditions. Different from traditional sliding mode control, the developed FSMC integrates two parts. The first part uses a fuzzy logic controller with two inputs and 25 rules as an equivalent controller while the second part is designed for an online adjusting of the switching controller’s gain using a fuzzy tuner with one input and one output. Simulation results showed the effectiveness of the proposed approach achieving maximum power point. The fuzzy sliding mode (FSM) controller takes less time to track the maximum power point, reduced the oscillation around the operating point and also removed the chattering phenomena that could lead to decrease the efficiency of the photovoltaic system.
Introduction- e - waste – definition - sources of e-waste– hazardous substances in e-waste - effects of e-waste on environment and human health- need for e-waste management– e-waste handling rules - waste minimization techniques for managing e-waste – recycling of e-waste - disposal treatment methods of e- waste – mechanism of extraction of precious metal from leaching solution-global Scenario of E-waste – E-waste in India- case studies.
Using recycled concrete aggregates (RCA) for pavements is crucial to achieving sustainability. Implementing RCA for new pavement can minimize carbon footprint, conserve natural resources, reduce harmful emissions, and lower life cycle costs. Compared to natural aggregate (NA), RCA pavement has fewer comprehensive studies and sustainability assessments.
CHINA’S GEO-ECONOMIC OUTREACH IN CENTRAL ASIAN COUNTRIES AND FUTURE PROSPECTjpsjournal1
The rivalry between prominent international actors for dominance over Central Asia's hydrocarbon
reserves and the ancient silk trade route, along with China's diplomatic endeavours in the area, has been
referred to as the "New Great Game." This research centres on the power struggle, considering
geopolitical, geostrategic, and geoeconomic variables. Topics including trade, political hegemony, oil
politics, and conventional and nontraditional security are all explored and explained by the researcher.
Using Mackinder's Heartland, Spykman Rimland, and Hegemonic Stability theories, examines China's role
in Central Asia. This study adheres to the empirical epistemological method and has taken care of
objectivity. This study analyze primary and secondary research documents critically to elaborate role of
china’s geo economic outreach in central Asian countries and its future prospect. China is thriving in trade,
pipeline politics, and winning states, according to this study, thanks to important instruments like the
Shanghai Cooperation Organisation and the Belt and Road Economic Initiative. According to this study,
China is seeing significant success in commerce, pipeline politics, and gaining influence on other
governments. This success may be attributed to the effective utilisation of key tools such as the Shanghai
Cooperation Organisation and the Belt and Road Economic Initiative.
We have compiled the most important slides from each speaker's presentation. This year’s compilation, available for free, captures the key insights and contributions shared during the DfMAy 2024 conference.
KuberTENes Birthday Bash Guadalajara - K8sGPT first impressionsVictor Morales
K8sGPT is a tool that analyzes and diagnoses Kubernetes clusters. This presentation was used to share the requirements and dependencies to deploy K8sGPT in a local environment.
Advanced control scheme of doubly fed induction generator for wind turbine us...IJECEIAES
This paper describes a speed control device for generating electrical energy on an electricity network based on the doubly fed induction generator (DFIG) used for wind power conversion systems. At first, a double-fed induction generator model was constructed. A control law is formulated to govern the flow of energy between the stator of a DFIG and the energy network using three types of controllers: proportional integral (PI), sliding mode controller (SMC) and second order sliding mode controller (SOSMC). Their different results in terms of power reference tracking, reaction to unexpected speed fluctuations, sensitivity to perturbations, and resilience against machine parameter alterations are compared. MATLAB/Simulink was used to conduct the simulations for the preceding study. Multiple simulations have shown very satisfying results, and the investigations demonstrate the efficacy and power-enhancing capabilities of the suggested control system.
2. ISSN: 2088-8694
IJPEDS Vol. 4, No. 1, March 2014 : 1 – 11
2
not easy to exploit for high output voltage. In this case, the used of parallel architecture with efficient
converters connected by a high voltage DC bus could offer increased performance [4, 9].
On the other hand, the interface between a low voltage power source and a high voltage DC output
is generally proposed by complex converter circuit as a cascaded structure composed of two or multiple sub-
converters allowing a high voltage ratio [10, 11].
The powerful conversion of low DC voltage from photovoltaic panels and/or wind turbines into a
HVDC grid [11, 12, 13] able to supply uninterruptible power [14], implicates simple, reliable and cheap high
efficiency converters while supplying voltages higher than 100V. Therefore, power converters must also
have new specifications in terms of efficiency, cost and environmental constraints to satisfy the quality
criteria required in renewable energy production.
Basic boost converters currently integrate a coil inductor and a freewheeling diode in series, and a
power switch system driving the output voltage. The principal causes of losses for converters working in
middle and high voltage ranges are due to these discrete elements. To describe the behaviour of these
elements, and to evaluate the losses and the overall efficiency, some standard models are largely used and
presented in literature [10, 15, 16]. Nevertheless, new recent data available in literature and/or given by the
manufacturers on power MOS transistors that can be integrated as commutation elements present new
possibilities for direct high voltage converter systems. In this case, the DC/DC conversion law available for
low voltage converters must be revised and suggests the redesign of new converter architecture. After the
evaluation of the losses in the inductance and in the diode, we have simulated the behaviour of the most usual
MOS transistors on Orcad and Proteus simulation software using manufacturer’s data. To determine the
dependence between the Rdson and Vdsmax of the transistors, we have included the bonding resistance in the
Gummel Poon model [16].
The presented methodology and conclusions of this study allow direct choices of performing
converter structures, by an optimization of the main power components, especially while keeping in view the
objective of the middle voltages, i.e. about the 150V to 500V usually implemented in usual PV systems. This
approach implicitly suggests a minimization of losses in cables used for interconnection by increasing the
output voltage on the HVDC bus, and consequently, allows a drastically decrease of currents in the power
bus. It results a decrease of the wires bus sections and of the generator cost.
Note that, even so this study is developed in view of a global search of the optimization of the
overall process in photovoltaic generator efficiency, we will not discuss the optimization of electric power
delivered by photovoltaic generators such as methods used for the MPPT (maximum power point tracking)
which are issues out of the scope of this paper.
2. BASIC BOOST PV CONVERTER
For PV applications, a number of interconnected grid inverters have been developed and used over
the last thirty years with various technological approaches [1, 2]. The general architecture of such distributed
PV system is represented in Figure 1 in case of a structure of eight panels associated with individual DC-DC
boost converters which are linked to a common DC-AC converter to the electrical grid.
Figure 1. Schematic representation of a distributed photovoltaic generator built with 8 PV panels associated
with dc/dc convertors connected via an inverter to the grid.
3. IJPEDS ISSN: 2088-8694
Basic MOSFET Based vs Couple-Coils Boost Converters for Photovoltaic Generators (Pierre Petit)
3
A basic boost DC/DC converter for DC load is shown in Figure 2. It includes DC voltage sources
represented as the photovoltaic generator, the input inductor L1 with series, Rs and parallel Rp resistors and
the input and output transfer capacitors, C1 and C2, respectively. In this diagram, D1 is the freewheeling
diode, M1 the power switch driven by a pulse width modulator (PWM).
The various components constituting the converter, as shown in Figure 2 must be adapted according
to the modulator working frequency, the converter input and output voltages, and the electrical power to be
converted. As we will see in the following, for high-level performance converter, the freewheeling diode,
which insures a passive operation, is replaced by an active switch in which the commutation is generally
provided by a MOSFET transistor.
Figure 2. Schematic diagram of a basic Step-Up converter integrated in a photovoltaic generator. PV is a
photovoltaic panel, PWM is the Pulse Width Modulator. C1, C2, Rp, Rs, L1, D1 and M1 are the discrete
elements constituting the electronic circuit (see the text).
On the basis of a photovoltaic system, the DC input voltage, which can be considered as generated
by a battery, is currently produced by photovoltaic interconnected panels in series, in parallel, or in a joint
series-parallel configurations but a single photovoltaic panel can also constitute it. Voltage at the input of the
converter is in the range of few tens of volts. The converter is sized as function of the required power output,
dependent on the input parameters, which are the irradiation level, the effective active surface, the orientation
and the efficiency of the panels, and the converter itself. Performances of the Maximum Power Point
Tracking driver, allowing the maximum power conversion, play also a non-negligible role in the overall
efficiency of the system.
For an interconnected photovoltaic system to the electrical network, the inverter is generally sized
up to a nominal power and to the output AC voltage of the network. Thus, the Step-Up is considered as an
interface, designed for a given output voltage, between the photovoltaic generator and the inverter.
Figure 3 shows the distribution of the currents in a classical Step Up converter. Figure 3.a in case of
passive energy transfer mode using a free-wheeling diode working in natural commutation and Figure 3.b, in
case of active energy transfer mode using a switch which can be MOSFET transistor. Figure 3.c shows the
current variation in the inductor. In this figure, a is defined as the duty cycle of the pulse width modulator.
With the help of the observed curves, we analyse further down the individual contribution of each
element in the global efficiency of the DC-DC converter. This study is essential before making any choice of
architecture for converters and PV systems as suggested in an example shown in Figure1. Conclusions of the
study of the existing architectures of converters also show the limitation of the actual systems and allowed us
to propose a high efficiency version of Step-Up structures, based on a commutation element integrating a
MOSFET.
2.1. The Coil Inductor Input Stage
Losses in the inductor have been studied in the past [18, 19]. Various origins for the inductor losses
can be listed. The three main losses are i) the magnetic losses and Foucault currents in the magnetic material
which influence on the Rp value, ii) the Joule effects in the coil, and iii) the Skin effect on the wire of the coil,
due to high frequencies and harmonics, which increases the Rs value. As we can observed in Figure 3c., the
shape of the current in the inductor presents variations amplitude referred as I. The minimization of the
dissipated power in the inductor will only happen if I is reduced to a minimum value. Thus, the level of
losses directly depends on physical parameters fixed during the inductor conception and fabrication, i.e. the
global dimensions and the constituting material of the magnetic circuit, the air-gap size, which is responsible
4. ISSN: 2088-8694
IJPEDS Vol. 4, No. 1, March 2014 : 1 – 11
4
of the storage of about 50% of the magnetic energy, the wire section, and the configuration of the various
coils. As these parameters depend on the frequency of the currents circulating in the coils, the losses too.
Figure 3. Intensity shape in a) a passive the free-wheeling diode switch stage, b) in the active MOSFET
switch stage, and c) in the inductor.
We can see that the performance improvement of a converter must include the lowering of losses in
the inductor, thus an optimization of its physical and electrical parameters. Nevertheless, this stage is not the
main key point of the converter efficiency because the charge is not directly connected to the inductor but to
the energy transfer output stage assuming the switch function. A discussion about losses in the output stage is
done further down.
2.2. Energy Transfer via a Passive Output Stage
The recovery energy transferred in a passive mode via a freewheeling diode is the simplest system
used from the beginning of energy conversion. The diode conducts current during the recovery phase and
automatically switches off during the next phase. The current, ID1 in the freewheeling diode is well described
in the literature [15, 16] and takes the form shown in Figure 3.a.
The main advantage of this solution is its simplicity due to the fact that the commutation operates
naturally at zero current, i.e. in a passive mode so it does not need any specific circuit or tracking strategy for
driving the output voltage. In view of a further minimization of losses, it is possible to use a low voltage
diode such as Schottky diode well adapted for this application due to its low voltage drop of about 0.2 volts.
Until recently, the main drawback of this solution was the too low reverse voltage supported by the diode.
Some new Schottky diodes in silicon carbide or silicon nitrite are, by now, available; these diodes support a
reverse voltage up to 600 volts, which makes it worth considering for medium voltage range converters
[4,18].
The power losses, Pd, in the diode follow the equation:
Pd = Vd 1 IinAvg (1)
5. IJPEDS ISSN: 2088-8694
Basic MOSFET Based vs Couple-Coils Boost Converters for Photovoltaic Generators (Pierre Petit)
5
where Vd is the direct voltage of the diode, is the duty cycle of the pulse width modulator, and IinAvg is the
mean current transmitted during the passing part of the cycle. L1 is the inductor as shown Figure 2. In those
systems the duty cycle, is in direct dependence on the input and output voltages Vin and Vout, respectively.
As an example of a photovoltaic high power converter specifications Vin =18VDC and Vout =500VDC,
IinAvg = 5A, gives after simulation of the losses in the diode, a power equal to Pd = 54mW. This power loss
corresponds to about 0.6% of the total power delivered by the converter.
2.3. Energy Transfer via an Active Output Stage
To increase the efficiency of the transfer output stage, the substitution of the freewheeling diode by
a transistor allowing an active control of the rectifying current is proposed as a solution [19]. This solution is
labelled a synchronous rectifier. It uses the inverse characteristics of a MOS transistor in direct mode with a
very low resistance Rdson. As an example, the Rdson of IRF2807, which can be used for this kind of
application, is equal to about 13m. This resistance induces a voltage drop three times lower than with an
usual Schottky diode. The current, IM1, passing through the transistor takes the form shown in Figure 3.b.
with the duty cycle, , expressed as
out
in
V
V
1 (2)
with Vin and Vout the input voltage and output voltages, respectively. In practice, Vout is lower than or equal to
Vdsmax. It should be noted that the holding voltage of this component must be carefully chosen to withstand
the value of the output voltage of the converter. The dependency of the duty cycle with the ratio Vin/Vout
implies that for high output voltages, can reach an important dissymmetry that also implicates high voltage
pulses in the output rectifying stage. Thus, for high output voltage values the gain in the efficiency that can
be expected with an active output stage becomes negligible. Nevertheless, in terms of commutation speed,
this solution is particularly advantageous because of the short recovery time, and thus overcomes the
drawbacks of the usual conventional diodes [17].
The energy losses in the active output stage are reduced almost to the Joule losses in the MOSFET
added by the losses in its control driver. In addition, two contra-effects complicate the system: the Miller’s
effect and the particular link to the control driver system, i.e. the need of a control for the switch of the
transistor in a perfectly synchronous mode. Within the input and output voltages and the power in a defined
range, the losses provided by an active switch is minimal compared to the solution based on a freewheeling
Schottky diode. On the other hand, the complexity of its implementation makes the system less reliable [10,
18].
In this architecture, the active output stage is the main key point of the converter because the output
charge is directly applied to the transistor assuming the switch function. For direct high voltage conversion,
the choice of the output electronic component of the output stage is quite difficult due to the increase of the
Joule losses and a judicious choice of this component constitutes an important issue for the increase of the
converter efficiency. The losses in this stage are mainly due to the Rdson resistance, active in direct mode. The
RMS value of the current IM1 through the switch is in the form shown in Fig. 3b. The RMS current in the
MOSFET with a duty cycle α appears in Equation 3.
IRMS = IinAvg
2
+
I 2
3
1
(3)
To evaluate the losses in the MOSFET during the active switch stage, we have analysed the
particular role of Rdson as function of the voltage Vdsmax applied to the transistor for various MOSFET
families. After identifying several transistors families compatible with high voltage converter applications,
above 200V, we have simulated the behaviour of many transistors with the Orcad and Proteus software to
find the relation between the parameter couples formed by Rdson and Vdsmax. The details of the analysis are
published elsewhere [20]. Nevertheless, for a self-consistent reading of the present work, we summarize the
main results. We have demonstrated by simulation that for any transistor likely to be the active element of a
switch of a boost converter, it exists a linear relation, Equation 4, between Rdson and Vdsmax.
maxdsg0dson VK+R=R (4)
6. ISSN: 2088-8694
IJPEDS Vol. 4, No. 1, March 2014 : 1 – 11
6
where R0 is the resistance approximating of the bonding contacts resistor ad Kg a proportionality constant.
Nevertheless, when the problem is the optimization of the switch stage for photovoltaic system, as function
of the input or output power of the converter, the choice of a transistor is quite delicate and the knowledge of
Kg for a particular transistor cannot give any information for other transistors belonging to the same
component family. In this case, we have shown [19] that this problem can be solved by the introduction of a
new proportional factor Kf and an exponent specific for a transistor family, yielding the transformation of
Equation 3 to a nonlinear relation.
maxdsf0dson VK+R=R (5)
We notice that the linear model for one transistor is a particular case of the general one for a given family
with Kf =Kg and with =1. The simulation of around thirty transistor families shows that is always above
one and often reaches two.
Considering a converter working in specific voltage and power ranges, the choice of a MOSFET in a
transistor family to optimize the efficiency of the active output stage, Equation 5 clearly shows that one can
expect an increase of Rdson as function of Vdsmax that implies a huge increase of losses in the MOSFET and, as
a consequence in the converter. To illustrate the losses in the switch stage, we have to evaluate the mean
power P0, that dissipates in the transistor. For the nonlinear model, Equation 5, with the expression of IRMS,
Equation 3, we obtain
3
1 2
0max0
max
0
2
dsf
ds
in I
+IVK+R
V
V
=P
(6)
In a Step-Up converter, the inductor was generally chosen with a sufficient size to obtain a good
smoothing of the current and, for P0 evaluation, we can assume that the system works near its nominal point
and neglect the term I in Equation 6. To illustrate the behaviour of a MOSFET used as an active switch
element in a PV converter, we have chosen the IRF2807 transistor family, which presents a good speed
commutation and Rdson compromise. Calculations were done for Vdsmax varying between 0 to 500 Volt and for
a current varying from 0 to 5A. The computation gives = 1.7, R0= 1.10-3
and Kf = 7.7 10-6
. Results of
simulations are illustrated in the Figures 4.a and 4.b, for full voltage and low voltage ranges, respectively.
Figure 4. Power losses in the switch (MOSFET) as function of IinAvg and Vdsmax in the full operating voltage
range. Insert: a zoom in the low voltage range.
The plots in Figure 4 clearly show the very rapid rise of losses when the voltage Vdsmax exceeds one
hundred volts, which is the case in PV applications as described above. The power losses increase very
rapidly and reach a maximum of 12.24W for high voltage, which gives a percentage of losses in the converter
7. IJPEDS ISSN: 2088-8694
Basic MOSFET Based vs Couple-Coils Boost Converters for Photovoltaic Generators (Pierre Petit)
7
around 12.7%. These losses are not compatible with the performance goals of a PV converter fixed lower
than 1.5% for the entire system. As we can see in the zoom reported Figure 4.b, obtained for Vdsmax below
50V, the power in the transistor does not exceed 133mW, corresponding to losses equal to approximately
0.1% of the total transmitted power, consistent with the performance goal of a PV converter.
In this first part of the presentation, we have analysed the efficiency of power converters specially
dedicated for photovoltaic energy conversion systems and working in the middle and high voltage ranges.
The losses in the coil inductor, the output transfer stage and in the switch of a boost converter were
considered. It will be noted that the aspects related to losses in the filter elements, capacitors and parasitic
capacitances were not taken into account. These elements involve low losses, but are sources of failures, due
to overheating.
The analysis and software simulations point out the importance of the power MOSFET used as the
commutation element in the entire efficiency of the system. With the actual MOSFET transistor families,
even the more recent ones, for high voltage conversion ratios and with output voltages above 100V, there is
no possibility to reach high conversion efficiencies. This is mainly due to high losses occurring in the
switching MOSFET, which presents a too high Rdson. These results exclude the direct conversion of
photovoltaic energy for high reliability voltages close to 300V. Within the actual performances of transistors
available in the market, for proper power conversion, it is essential to use low-voltage MOSFETs working in
the 50V to 100V range. For direct high voltage DC/DC converter, it will therefore be necessary to change the
structure of the converter, to operate at reduced voltage for the switching transistor, while producing a high
output voltage. Among the several possible structures, we suggest converter architecture based on a coupled-
coils arrangement. Hereafter, we present and analyse the performance of such a system.
3. COUPLED-COILS BASED BOOST PV CONVERTER
In order to conciliate the low voltage require insuring a high efficiency of the MOSFET switch
transistor and the high output voltage, we propose to add a second coil L2 strongly magnetically coupled to
the first one L1. This structure, named Couple-Coils Boost Converter, CC-BC is very well known and is used
for example, to generate the TV high voltages supplying cathode ray tube and the originality consists in the
implantation of such a structure in boost converters for photovoltaic applications with their specific
constraints.
The principle of a CC-BC is based on the electrical load of the first inductor L1 with the input
energy when S1 is closed, followed by the restitution in the second inductor L2 when S1 is opened. The
introduction of the second inductor L2 in the output stage increases the overvoltage effect. The schema
associated to this solution is reported in Figure 5 where R1 and R2 are the resistors of the two inductances L1
and L2, respectively. In a first approach, we describe the system and point out the method to optimize the duty
cycle by considering an ideal electronic system without losses due to the parallel equivalent resistors or
parasitic discrete elements. The real operation of the converter will be presented in the second part.
Figure 5. Electronic diagram of the ideal CC-BC. The MOSFET transistor, S1, is connected at the middle of
two magnetically coupled inductors.
The energy stored in the inductors, WL is calculated by the classical equation
2
11
2
1
IL=WL1 (7)
8. ISSN: 2088-8694
IJPEDS Vol. 4, No. 1, March 2014 : 1 – 11
8
where
R
N
=L
2
1
1 (8)
where, considering the system based on an autotransformer with a coupling coefficient equal to 1, i=1, 2, 1+2
linked to the active inductors considered, R is the reluctance of the magnetic circuit and N the number of
turns of the inductors.
Considering the case of CC-BC adjusted to a well-balanced duty cycle = 50%, we report in
Figure 6, the repartition of the currents in the two inductors and in the active switch.
Figure 6. Typical currents in the CC-BC: (a) current in the input inductor L1, (b) current in the MOSFET used
as a switch, (c) current in the second inductor L2
We can explain and comment the operation principle as follow. At first, when S1 is closed and
taking into account the coupling sign of the coils, only L1 is crossed over by the input current. The index i is
equal to 1 in Equations 7 and 8. The current frame in the inductor is the same as the one provided in a basic
boost converter, following a linear increase, as shown in Figure 6a as long as the inductor L1 is not on
saturation. In case of saturation of L1, the decrease of the inductor will induce a non-linear evolution of the
current in the coil. At second, when S1 opens, both coupled inductors are implicated in the restitution current
and the index i is equal to 1+2 in Equations 7 and 8, which indicate that as the recovered energy is done in a
higher self-inductance, the decrease rate is different according to the basic boost converter. The abrupt
variation of the current IL1 in the inductor L1 during this phase is explained by the instantaneous transfer of
the initial energy from L1 to L1 + L2 adding a large number of turns in the system. The efficiency of the CC-
BC is improved by an adjustment of the duty cycle at about 50%, as shown in Figure 6. This symmetry
suggests the equilibrium between the loading phase and the recovered energy phase. This can be done by an
adjustment of the transformation ratio by a judicious choice of the number of turns. From Equation 7 and
considering the conservation of the energy in the inductors during the two phases of a cycle, we can write
m+=
N
N+N
=
I
I 2
L2
e
1
1
1
max
max
(9)
where m, the transformation ratio of the transformer equals to N1/N2. The currents IL1max and IL2max are
defined during the two phases and they are linked to the duty cycle by respectively.
9. IJPEDS ISSN: 2088-8694
Basic MOSFET Based vs Couple-Coils Boost Converters for Photovoltaic Generators (Pierre Petit)
9
1
1
max
L
V
T=IL1 and
tot
L2maxL2
L
VV
T=I=I 12
max 1
(10)
Finally, according to the Eqs. 9 and 10, we can write
totL
VV
=m+ 12
1
1
(11)
Thus, Equation 11 shows that when considering the voltage in the inductors, we can choose the
transformation ratio allowing an adjustment of the duty cycle to about 50% of the total cycle duration.
We have simulated with Orcad such a CC-BC in a real situation, i.e. with all parasitic elements
neglected in the first theoretical approach presented above, with the practical values of the discrete elements
reported in the schema of Figure 7.
Figure 7. Electronic diagram of the ideal CC-BC including all parasitic elements.
We have considered in the simulation the connection of a converter to a load with an output voltage
equal to 150VDC. The results of the simulations of the current in the MOSFET and the voltage Vds, recorded
at the middle point of the set-up, i.e. between the two coils, are shown in Figure 8.
Figure 8. Chronograms of current and voltage in the CC-BC
We clearly observe some resonance phenomena in the two coils witch perturb the current and which
appear during the all cycle. In the first phase of the switching cycle, we can observe a low frequency pseudo-
10. ISSN: 2088-8694
IJPEDS Vol. 4, No. 1, March 2014 : 1 – 11
10
oscillation of the current originate from the diode capacity D3 and C. This transient phenomenon is
superposed by a second oscillation caused by the interruption of the current in the MOSFET, the capacity of
which coupled with the leakage inductor of the autotransformer generates resonances. In the second part of
the cycle, when the switch opens, we observe a high frequency pseudo-oscillation for the recovery current
and for the voltage Vds. The peak of the over-voltage, Vds-peak induced by these resonances can reach the same
level as the output voltage used for the boost, e.g. it can reach 75V in the present set-up, as shown in Fig. 8.
This oscillating phenomena in real system yields to use a high voltage MOSFET, which thus raises, as sawn
before, the problem of the presence of a transistor with a high Rdson, causing a drastic losses increase and
performance deterioration of the converter.
As we have shown in this study based on simulation and measurements done on a real prototype
dedicated for photovoltaic applications, the first innovation of the CC-BC architecture, comparing to the
basic step-up converter is the possibility of this system to adjust the duty cycle to 50% in spite of imposed
external input and output voltages. The second advantage of this structure is the use of a low voltage
MOSFET to insure the switching function even for high output voltage assuming high efficiency
conversions.
4. CONCLUSION
The powerful conversion of low DC voltage from photovoltaic panels or wind turbine into a HVDC
grid able to supply uninterruptible power, implicates simple, reliable and cheap high efficiency converters
while supplying voltages higher than 100V. Such high voltage architectures have been considered until
recently, as a technologic lock in classical Boosts. In the present study, we have shown, thanks to simulations
and measurements on electronic prototypes, that the use of an autotransformer coupled driven by a smart
PWM control with a nominal duty cycle near 50% presents a real progress in term of efficiency compared to
the basic boost converter dedicated to low and medium power conversion. The consideration of the non-
linear relation between Vdsmax and Rdson of the MOSFET used as the switch in the converter allows modelling
of the behaviour of such a boost converter. In this study, some experimental parameters slightly affect the
obtained results, such as the coupling coefficient in the autotransformer, which is supposed equal to one and
the current-voltage converter, which introduces joules losses. An additional study must be performed to
recover the parasitic energy stored in the leakage inductor especially when the coupling coefficient of the
coupled coils differs from 1 as in the low-coupled coils.
Different versions of the two improved Step-Up boost converters will be successfully tested with the
individual connection of 12V and 40V PV panels to a grid able to supply a standard inverter.
ACKNOWLEDGEMENTS
The authors gratefully acknowledge the Institut Universitaire de Technology, IUT of Thionville-
Yutz, and particularly the Director, Prof. J. Falla and the Chief of Department GIM, Y. Gillet for the
financially support and for the facilities offer in these researches.
REFERENCES
[1] M Calais, VG Agelidis. “Multilevel converters for single-phase grid connected photovoltaic systems-an overview”.
Proc. IEEE Intern. Symp. Industr. Electron. Pretoria, South Africa 1 (1998) 224-229.
[2] F Blaabjerg, Z Chenn, SB Kjaer. “Power electronics as efficient interface in dispersed power generation systems”.
IEEE Trans. Power. Electron. 19, 5 (2004) 1184-1194.
[3] M Calais, JMA Myrzik, VG Agelidis. “Inverters for single phase grid connected photovoltaic systems overview
and prospects”. Proc. 17th PV Solar Ener. Conf. Exhibit. Munich Germany (2001).
[4] Q Zhao, FC Lee. “High-Efficiency High Step-Up DC–DC Converters”. IEEE Trans. Power Electron. 18, 1 (2003).
[5] N Kaushika, N Gautam. “Energy yield simulations of interconnected solar PV arrays”. IEEE Trans. Ener. Conver.
18 (2003) 127-134.
[6] W Hermann, W Wiesner, W Vaassen. “Hot spot investigations on PV modules-new concepts for a test standard
and consequences for module design with respect to bypass diodes”. 26th
IEEE Photovolt. Specialists Conf. (1997)
1129-1132.
[7] M Di Santo, A Vaccaro, D Villacci, E Zimeo. “A distributed architecture for online power systems security
analysis”. IEEE Trans. on Industrial Electron. 51, 12 (2004) 1238-1248.
[8] TS Ustun, C Ozansoy, A Zayegh. “Recent developments in microgrids and example cases around the world”.
Renewable and Sustainable Energy Rev. 15, 8 (2011) 4030-4041.
[9] A De Bernardinis, MC Péra, J Garnier, D Hissel, G Coquery, JM Kauffmann. “Fuel cells multi-stack power
architectures and experimental validation of 1 kW parallel twin stack PEFC generator based on high frequency
11. IJPEDS ISSN: 2088-8694
Basic MOSFET Based vs Couple-Coils Boost Converters for Photovoltaic Generators (Pierre Petit)
11
magnetic coupling dedicated to on board power unit”. Energy Conversion and Management. 49, 8 (2008) 2367-
2383.
[10] A Shahin, B Huang, JP Martin, S Pierfederici, B Davat. “New non-linear control strategy for non-isolated DC/DC
converter with high voltage ratio”. Energy Conversion and Management. 51, 1 (2010) 56-63.
[11] P Petit, M Aillerie, A Zegaoui, JP Sawicki, JP Charles. “Rdson behavior in various MOSFET families”. IEEE
Industr. Electron. ISIE (2011) 353 - 357.
[12] RG Walker, PC Sernia. “Cascaded DC–DC Converter Connection of Photovoltaic Modules”. IEEE Trans. on
Power Electron. 8, 4 (2004) 1130-1139.
[13] F Schettler, H Huang, N Christl. “HVDC transmission systems using voltage sourced converters design and
applications”. Power Engineering Society Summer Meeting, IEEE. (2000), Volume 2, 715-720.
[14] J Devishree, J Anbalagan, A. “Photovoltaic Uninterruptible Power Supply System Synchronized to the Grid”, J.
Appl. Scien. 6, 12 (2006) 2673-2675.
[15] G Stojcic, C Nguyen, G Stojcic and C Nguyen. “MOSFET synchronous rectifiers for isolated, board-mounted DC-
DC converters”. Telecommunications Energy Conference, INTELEC (2000). IEEE. 258-266.
[16] H Goebel. “A unified method for modeling semiconductor power devices”. IEEE Trans Power Electron. 9 (1994)
497-505.
[17] J Shen, Y Xiong, X Cheng, Y Fu, P Kumar. “Power MOSFET switching loss analysis: a new insight, Industry”.
Applications Conference, 2006. 41st IAS Annual Meeting. Conference Record of the 2006 IEEE, Volume 3 1438-
1442.
[18] H Dwight. “Proximity effect in wires, mutual inductance of filamentary circles, mutual inductance of two thin disk
coils, magnetic field from round coil of small rectangular cross section, in Electrical Coils and Conductors”.
McGraw-Hill Inc., New York. (1946) 192-292.
[19] R Watson, FC Lee, GC. Hua. “Utilization of an active-clamp circuit to achieve soft switching in flyback
onverters”. Proc. IEEE-PESC Annual Meeting (1994) 909-916.
[20] M El-Markabi, E Freeman. “Electromagnetic properties of a circular cylindrical coil in a set of planar
ferromagnetic regions”. IEE Proc 129, A8 (1982) 582-589.