The document describes an extended-phase-shift (EPS) control method for isolated bidirectional DC-DC converters used in power distribution for microgrids. EPS control adds an inner phase-shift ratio between switch driving signals in addition to the outer phase-shift ratio of traditional phase-shift control. This decreases the backflow power effect seen in traditional control, expanding the power regulating range and reducing current stress compared to traditional control. The document analyzes the operation principle and eight modes of the converter under EPS control through circuit diagrams and mathematical equations.
This paper presents the design and operation of three-stage buck-boost converter with high gain soft switching using closed loop proportional integral (PI) controller. The proposed converter is designed by arranging three identical buck-boost converters working in parallel. The converter units are connected to each other by an inductor as a bridge. This inductor plays a vital role in soft switching operation of converter by maintaining the voltage applied to switches at zero voltage at switching intervals, i.e., the zero-voltage switching (ZVS). The closed-loop system is designed by PI controller, and it maintains the output constant irrespective of changes in input, and the system becomes stable. The proposed converter is efficient in reducing switching losses, leading to improved converter efficiency. Due to parallel operation of three identical converters, the output voltage and input current contain fewer ripples than those of a single converter with same specifications. Proposed converter is more economical and reliable with simpler structure as it utilizes only two inductors as extra elements. The design and analysis of proposed circuit has been carried out in MATLAB Simulink by operating the circuit in various modes.
One of the preferred choices of electronic power conversion for high power applications are multilevel inverters topologies finding increased attention in industry. Cascaded H-Bridge multilevel inverter is one of these topologies reaching the higher output voltage, power level and higher reliability due to its modular topology. Level Shifted Carrier Pulse Width Modulation (LSCPWM) and Phase Shifted Carrier Pulse Width Modulation are used generally for switching cascaded H-bridge (CHB) multilevel inverters. This paper compares LSCPWM and PSCPWM in terms of total harmonics distortion (THD) and output voltage among inverter cells. Simulation for 21-level CHB inverter is carried out in MATLAB/SIMULINK and simulation results are presented.
The projected diode assisted Neutral Point Diode Clamed (NPC-MLI) with the photovoltaic system produces a maximum voltage gain that is comparatively higher than those of other boost conversion techniques. This paper mainly explores vector selection approach pulse-width modulation (PWM) strategies for diode-assisted NPC-MLI to obtain a maximum voltage gain without compromising in waveform quality. To obtain a high voltage gain maximum utilization of dc-link voltage and stress on the power switches must be reduced. From the above issues in the diode assisted NPC-MLI leads to vector selection approach PWM technique to perform capacitive charging in parallel and discharging in series to obtain maximum voltage gain. The operation principle and the relationship of voltage gain versus voltage boost duty ratio and switching device voltage stress versus voltage gain are theoretically investigated in detail. Owing to better performance, diode-assisted NPC-MLI is more promising and competitive topology for wide range dc/ac power conversion in a renewable energy application. Furthermore, theoretically investigated are validated via simulation and experimental 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.
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
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.
Modeling and Analysis of Transformerless High Gain Buck-boost DC-DC ConvertersIAES-IJPEDS
This paper proposes a transfomerless switched capacitor buck boost converter model, which provides higher voltage gain and higher efficiency when compared to the conventional buck boost converter. The averaged model based on state- space description is analyzed in the paper. The simulation results are presented to confirm the capability of the converter to generate high voltage ratios. The comparison between the proposed model and the traditional model is also provided to reveal the improvement. The proposed converter is suitable for for a wide application which requires high step-up DC-DC converters such as DC micro-grids and solar electrical energy.
The use of distributed generation (DG) within distribution systems has increased for the last two decades due to worldwide increase in demand for electricity and governmental policy change from “conventional” energy to “green” energy. High levels of penetration of DG have many significant benefits but also come with many drawbacks such as voltage drop and power losses. This study presents the impact of DG at different locations in a distribution feeder in terms of the feeder voltage profile. A radial distribution system is simulated using PSCAD/EMTDC simulation software while changing the size and location of DG in the system. The obtained results are used for better understanding on the impact of DG on voltage profile in radial distribution feeder.
This paper presents the design and operation of three-stage buck-boost converter with high gain soft switching using closed loop proportional integral (PI) controller. The proposed converter is designed by arranging three identical buck-boost converters working in parallel. The converter units are connected to each other by an inductor as a bridge. This inductor plays a vital role in soft switching operation of converter by maintaining the voltage applied to switches at zero voltage at switching intervals, i.e., the zero-voltage switching (ZVS). The closed-loop system is designed by PI controller, and it maintains the output constant irrespective of changes in input, and the system becomes stable. The proposed converter is efficient in reducing switching losses, leading to improved converter efficiency. Due to parallel operation of three identical converters, the output voltage and input current contain fewer ripples than those of a single converter with same specifications. Proposed converter is more economical and reliable with simpler structure as it utilizes only two inductors as extra elements. The design and analysis of proposed circuit has been carried out in MATLAB Simulink by operating the circuit in various modes.
One of the preferred choices of electronic power conversion for high power applications are multilevel inverters topologies finding increased attention in industry. Cascaded H-Bridge multilevel inverter is one of these topologies reaching the higher output voltage, power level and higher reliability due to its modular topology. Level Shifted Carrier Pulse Width Modulation (LSCPWM) and Phase Shifted Carrier Pulse Width Modulation are used generally for switching cascaded H-bridge (CHB) multilevel inverters. This paper compares LSCPWM and PSCPWM in terms of total harmonics distortion (THD) and output voltage among inverter cells. Simulation for 21-level CHB inverter is carried out in MATLAB/SIMULINK and simulation results are presented.
The projected diode assisted Neutral Point Diode Clamed (NPC-MLI) with the photovoltaic system produces a maximum voltage gain that is comparatively higher than those of other boost conversion techniques. This paper mainly explores vector selection approach pulse-width modulation (PWM) strategies for diode-assisted NPC-MLI to obtain a maximum voltage gain without compromising in waveform quality. To obtain a high voltage gain maximum utilization of dc-link voltage and stress on the power switches must be reduced. From the above issues in the diode assisted NPC-MLI leads to vector selection approach PWM technique to perform capacitive charging in parallel and discharging in series to obtain maximum voltage gain. The operation principle and the relationship of voltage gain versus voltage boost duty ratio and switching device voltage stress versus voltage gain are theoretically investigated in detail. Owing to better performance, diode-assisted NPC-MLI is more promising and competitive topology for wide range dc/ac power conversion in a renewable energy application. Furthermore, theoretically investigated are validated via simulation and experimental 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.
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
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.
Modeling and Analysis of Transformerless High Gain Buck-boost DC-DC ConvertersIAES-IJPEDS
This paper proposes a transfomerless switched capacitor buck boost converter model, which provides higher voltage gain and higher efficiency when compared to the conventional buck boost converter. The averaged model based on state- space description is analyzed in the paper. The simulation results are presented to confirm the capability of the converter to generate high voltage ratios. The comparison between the proposed model and the traditional model is also provided to reveal the improvement. The proposed converter is suitable for for a wide application which requires high step-up DC-DC converters such as DC micro-grids and solar electrical energy.
The use of distributed generation (DG) within distribution systems has increased for the last two decades due to worldwide increase in demand for electricity and governmental policy change from “conventional” energy to “green” energy. High levels of penetration of DG have many significant benefits but also come with many drawbacks such as voltage drop and power losses. This study presents the impact of DG at different locations in a distribution feeder in terms of the feeder voltage profile. A radial distribution system is simulated using PSCAD/EMTDC simulation software while changing the size and location of DG in the system. The obtained results are used for better understanding on the impact of DG on voltage profile in radial distribution feeder.
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.
A Novel Power Factor Correction Rectifier for Enhancing Power QualityIJPEDS-IAES
In this paper, the disturbances in power system due to low quality of power
are discussed and a current injection method to maintain the sinusoidal input
current which will reduce the total current harmonic distortion (THD) as well
as improve the power factor nearer to unity is proposed. The proposed
method makes use of a novel controlled diode rectifier which involves the
use of bidirectional switches across the front-end rectifier and the operation
of the converter is fully analyzed. The main feature of the topology is low
cost, small size, high efficiency and simplicity, and is excellent for
retrofitting front-end rectifier of existing ac drives, UPS etc. A novel strategy
implementing reference compensation current depending on the load
harmonics and a control algorithm for three-phase three-level unity PF
rectifier which draws high quality sinusoidal supply currents and maintains
good dc link- voltage regulation under wide load variation. The proposed
technique can be applied as a retrofit to a variety of existing thyristor
converters which uses three bidirectional switches operating at low frequency
and a half-bridge inverter operating at high frequency .The total power
delivered to the load is processed by the injection network, the proposed
converter offers high efficiency and not only high power factor but also the
Total Harmonic Distortion is reduced. Theoretical analysis is verified by
digital simulation and a hardware proto type module is implemented in order
to confirm the feasibility of the proposed system. This scheme in general is
suitable for the common variable medium-to high-power level DC load
applications.
This document summarizes a research paper that proposes a solid-state transformer (S2T) using a single phase matrix converter (SPMC). The S2T aims to address limitations of conventional transformers such as size, weight, environmental issues. The proposed S2T design uses two SPMCs - one operating at 1 kHz to generate high frequency current on the primary side, and the other at 50 Hz to produce low frequency voltage on the secondary side. A switching algorithm is presented to address commutation problems when using inductive loads. The S2T design and switching control are simulated in MATLAB/Simulink. Results show the S2T design can help minimize size and losses while achieving optimal efficiency compared to conventional approaches
6.[36 45]seven level modified cascaded inverter for induction motor drive app...Alexander Decker
1) The document presents a modified cascaded multilevel inverter topology for induction motor drive applications that reduces the number of switches compared to conventional designs.
2) The proposed topology uses 7 switches and 3 diodes to generate 7 voltage levels, whereas conventional designs require 12 switches. This reduces switching losses, cost, and complexity.
3) Simulation and experimental results show the proposed design can generate 7 voltage levels to drive an induction motor. FFT analysis shows lower total harmonic distortion compared to conventional designs.
Design and Performance of a Bidirectional Isolated Dc-Dc Converter for Renewa...IOSR Journals
1) The document describes a bidirectional isolated DC-DC converter for renewable power systems. The proposed converter uses a coupled inductor with the same winding turns on the primary and secondary sides, allowing for higher step-up and step-down voltage gains than conventional bidirectional converters.
2) A simulation of the proposed converter in a photovoltaic system is implemented in Simulink. The simulation results show the input voltage from the solar panel and output voltage in both forward and reverse modes of operation.
3) A quasi-optimal design method is presented to minimize conduction losses by reducing the RMS current value and extend zero-voltage switching to improve conversion efficiency. Duty cycle control is used to achieve this while accommodating variations in
International Journal of Engineering Research and Applications (IJERA) aims to cover the latest outstanding developments in the field of all Engineering Technologies & science.
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
Transformer less Boost Converter Topologies with Improved Voltage Gain Operat...IJMER
In this project, a new step up converter proposed in a recent work is analyzed, designed, simulated with MATLAB Simulink. Conventional dc–dc boost converters are unable to provide high step-up voltage gains due to the effect of power switches, rectifier diodes, and the equivalent series resistance of inductors and capacitors. This paper proposes transformer less dc–dc converters to achieve high step-up voltage gain without an extremely high duty ratio. In the proposed converters, two inductors with the same level of inductance are charged in parallel during the switch-on period and are discharged in series during the switch-off period. The structures of the proposed converters are very simple.
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
This document summarizes a research article that proposes using a Unified Power Quality Compensator (UPQC) device to regulate voltage and mitigate fluctuations at a weak grid connection to a wind farm. The UPQC uses internal control strategies to regulate the voltage at the wind farm terminals using its series converter, and uses its shunt converter to filter wind farm power and prevent voltage fluctuations. The control strategy manages active and reactive power sharing between the series and shunt converters through a common DC link. Simulation results showed the UPQC approach effectively regulated voltage during load changes and rejected power fluctuations from tower shadow effects at the wind turbines.
This document summarizes a study that proposes a new method to improve voltage profiles in power systems by determining optimal locations for reactive power compensation devices like capacitor banks. The method utilizes modal analysis and calculates a reactive participation index (RPI) to identify buses that would most effectively improve voltage levels when compensated. The method is tested on the South Sulawesi power system in Indonesia, identifying key under-voltage buses. Capacitors are added iteratively at the buses with the highest RPI until all voltages are within limits. The results demonstrate improved voltage profiles and increased stability compared to alternative configurations.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
Power management by using multiport dc – dc converter for renewable energyeSAT Journals
Abstract
This paper proposes, power management of different types of renewable energy source is controlled by multiport DC-DC
converter. In this each port of the converter is connected with controller switch to control the source input of converter. This is
reduces the turn off switching losses by soft switching. The high frequency switches are used to control the power flow. This
converter is proposed to control the hybrid energy generating system, with the ability of bidirectional power flow between battery
and load. The diode bridge rectifier is applicable for high switching frequency operation with realizable component compare with
existing converter. The efficiency of the converter is verified through MATLAB simulation. The operation and design performance
is explained briefly. The proposed converter has reliability operate simultaneous power generation from different renewable
energy source. Fuzzy controller controls the direction of power flow and load voltage of the converter.
Keywords: Isolator, high frequency link, soft switching, multiport converter, PV panel, wind turbine generator (WTG
A new closed loop AC to DC ĈUK converter is presented in this paper. The conventional ĈUK AC to DC converter has no feedback circuit. Thereby, the output voltage of the converter changes while changing the load. The proposed closed loop converter can regulate voltage with the variation of load over a wide range. Moreover, the power factor and Total Harmonic Distortion (THD) of the supply side current found quite satisfactory from this closed loop ĈUK converter. The converter operates in four steps with a different combination of voltage polarities and switching states. The feedback path consists of a voltage control loop and a current control loop. The closed loop ĈUK converter in this study is compared with the open loop version. Additionally, the comparison is made with the conventional converter of the same topology. The effectiveness in terms of power factor and THD of the proposed converter is verified using simulation results.
Integration of Unified Power Quality Controller with DGIJRST Journal
This paper proposes integrating a Unified Power Quality Controller (UPQC) with a distributed generator (DG). The UPQC consists of series and shunt inverters connected to a common DC link, and can compensate for power quality issues like voltage sags/swells, harmonics, and reactive power. Integrating a DG connected through a rectifier to the DC link allows the system to operate in two modes: interconnected mode where the DG supplies power to the source and load, and islanding mode where the DG only supplies the load during a source voltage interruption. Simulations show the integrated system can compensate for voltage sags and swells in both forward and reverse power flow modes between the DG and
A ZVS Interleaved Boost AC/DC Converter Using Super Capacitor Power for Hybri...IJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
Single Phase Matrix Converter for Input Power Factor Improvementiosrjce
IOSR Journal of Electrical and Electronics Engineering(IOSR-JEEE) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of electrical and electronics engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in electrical and electronics engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Voltage-current Double Loop Control Strategy for Magnetically Controllable Re...Kashif Mehmood
Voltage regulation depending on reactive power
compensation is the main feature of the AC power supply
system. Magnetically controllable reactors (MCR) are
becoming a growing demand for this purpose. The structure
and working principles of MCR are analysed in this paper
while a simulation model is established. The reactive power
compensation strategy based on a single loop voltage control
system (SLVCS) is presented and a double loop
voltage-current control system (DLVCCS) is proposed. A
comprehensive scenario is developed to mitigate reactive power
compensation by using the proposed controls. Simulation
results substantiate that proposed controls of MCR has a faster
response in comparison to the traditional control, and it
provides the least voltage variation at the line end. It also
shows that the proposed control on MCR meet the desired
objective of the voltage regulation and provides flexibility to ac
transmission system
Analysis of Variable Speed PFC Chopper FED BLDC Motor DriveIJPEDS-IAES
This paper provides the detailed analysis of the DC-DC chopper fed Brushless DC motor drive used for low-power applications. The various methods used to improve the power quality at the ac mains with lesser number of components are discussed. The most effective method of power quality improvement is also simulated using MATLAB Simulink. Improved method of speed control by controlling the dc link voltage of Voltage Source Inverter is also discussed with reduced switching losses. The continuous and discontinuous modes of operation of the converters are also discussed based on the improvement in power quality. The performance of the most effective solution is simulated in MATLAB Simulink environment and the obtained results are presented.
This document discusses optimizing the energy production of an autonomous photovoltaic (PV) system with a simple charge regulator. The study determines the optimal open circuit voltage range of the PV field for 12V and 24V storage systems. Mathematical models are developed for PV modules, storage batteries, and charge regulators. Simulation results show that a PV field's open circuit voltage between 16-23V optimizes energy production for a 12V system, and between 34-43V for a 24V system, under standard test conditions. The optimal voltage ensures the intersection point between the PV and battery voltage-current characteristics is near the PV module's maximum power point.
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.
Comparison of an Isolated bidirectional Dc-Dc converter with and without a Fl...IOSR Journals
This document compares an isolated bidirectional DC-DC converter with and without a flyback snubber through simulation and hardware implementation. It begins with an introduction to isolated bidirectional converters and the problem of voltage spikes caused by transformer leakage inductance. It then describes the operation and components of the converter both with and without a flyback snubber. Simulation results show that the flyback snubber reduces voltage spikes by 78-80% by clamping the voltage. Hardware results for boost mode operation with a flyback snubber are also presented and agree with simulation.
This document summarizes a grid-connected photovoltaic power system that uses a boost-half-bridge converter. The system aims to efficiently transfer power from a solar PV array to the electric grid. It consists of two main stages - a boost-half-bridge DC-DC converter that steps up the low-voltage solar output, and a full-bridge inverter that feeds a sinusoidal current into the grid via an LCL filter. The boost-half-bridge converter provides galvanic isolation and a high step-up ratio with minimal components. Maximum power point tracking is performed to optimize solar energy extraction while limiting transient effects on efficiency.
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.
A Novel Power Factor Correction Rectifier for Enhancing Power QualityIJPEDS-IAES
In this paper, the disturbances in power system due to low quality of power
are discussed and a current injection method to maintain the sinusoidal input
current which will reduce the total current harmonic distortion (THD) as well
as improve the power factor nearer to unity is proposed. The proposed
method makes use of a novel controlled diode rectifier which involves the
use of bidirectional switches across the front-end rectifier and the operation
of the converter is fully analyzed. The main feature of the topology is low
cost, small size, high efficiency and simplicity, and is excellent for
retrofitting front-end rectifier of existing ac drives, UPS etc. A novel strategy
implementing reference compensation current depending on the load
harmonics and a control algorithm for three-phase three-level unity PF
rectifier which draws high quality sinusoidal supply currents and maintains
good dc link- voltage regulation under wide load variation. The proposed
technique can be applied as a retrofit to a variety of existing thyristor
converters which uses three bidirectional switches operating at low frequency
and a half-bridge inverter operating at high frequency .The total power
delivered to the load is processed by the injection network, the proposed
converter offers high efficiency and not only high power factor but also the
Total Harmonic Distortion is reduced. Theoretical analysis is verified by
digital simulation and a hardware proto type module is implemented in order
to confirm the feasibility of the proposed system. This scheme in general is
suitable for the common variable medium-to high-power level DC load
applications.
This document summarizes a research paper that proposes a solid-state transformer (S2T) using a single phase matrix converter (SPMC). The S2T aims to address limitations of conventional transformers such as size, weight, environmental issues. The proposed S2T design uses two SPMCs - one operating at 1 kHz to generate high frequency current on the primary side, and the other at 50 Hz to produce low frequency voltage on the secondary side. A switching algorithm is presented to address commutation problems when using inductive loads. The S2T design and switching control are simulated in MATLAB/Simulink. Results show the S2T design can help minimize size and losses while achieving optimal efficiency compared to conventional approaches
6.[36 45]seven level modified cascaded inverter for induction motor drive app...Alexander Decker
1) The document presents a modified cascaded multilevel inverter topology for induction motor drive applications that reduces the number of switches compared to conventional designs.
2) The proposed topology uses 7 switches and 3 diodes to generate 7 voltage levels, whereas conventional designs require 12 switches. This reduces switching losses, cost, and complexity.
3) Simulation and experimental results show the proposed design can generate 7 voltage levels to drive an induction motor. FFT analysis shows lower total harmonic distortion compared to conventional designs.
Design and Performance of a Bidirectional Isolated Dc-Dc Converter for Renewa...IOSR Journals
1) The document describes a bidirectional isolated DC-DC converter for renewable power systems. The proposed converter uses a coupled inductor with the same winding turns on the primary and secondary sides, allowing for higher step-up and step-down voltage gains than conventional bidirectional converters.
2) A simulation of the proposed converter in a photovoltaic system is implemented in Simulink. The simulation results show the input voltage from the solar panel and output voltage in both forward and reverse modes of operation.
3) A quasi-optimal design method is presented to minimize conduction losses by reducing the RMS current value and extend zero-voltage switching to improve conversion efficiency. Duty cycle control is used to achieve this while accommodating variations in
International Journal of Engineering Research and Applications (IJERA) aims to cover the latest outstanding developments in the field of all Engineering Technologies & science.
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
Transformer less Boost Converter Topologies with Improved Voltage Gain Operat...IJMER
In this project, a new step up converter proposed in a recent work is analyzed, designed, simulated with MATLAB Simulink. Conventional dc–dc boost converters are unable to provide high step-up voltage gains due to the effect of power switches, rectifier diodes, and the equivalent series resistance of inductors and capacitors. This paper proposes transformer less dc–dc converters to achieve high step-up voltage gain without an extremely high duty ratio. In the proposed converters, two inductors with the same level of inductance are charged in parallel during the switch-on period and are discharged in series during the switch-off period. The structures of the proposed converters are very simple.
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
This document summarizes a research article that proposes using a Unified Power Quality Compensator (UPQC) device to regulate voltage and mitigate fluctuations at a weak grid connection to a wind farm. The UPQC uses internal control strategies to regulate the voltage at the wind farm terminals using its series converter, and uses its shunt converter to filter wind farm power and prevent voltage fluctuations. The control strategy manages active and reactive power sharing between the series and shunt converters through a common DC link. Simulation results showed the UPQC approach effectively regulated voltage during load changes and rejected power fluctuations from tower shadow effects at the wind turbines.
This document summarizes a study that proposes a new method to improve voltage profiles in power systems by determining optimal locations for reactive power compensation devices like capacitor banks. The method utilizes modal analysis and calculates a reactive participation index (RPI) to identify buses that would most effectively improve voltage levels when compensated. The method is tested on the South Sulawesi power system in Indonesia, identifying key under-voltage buses. Capacitors are added iteratively at the buses with the highest RPI until all voltages are within limits. The results demonstrate improved voltage profiles and increased stability compared to alternative configurations.
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Power management by using multiport dc – dc converter for renewable energyeSAT Journals
Abstract
This paper proposes, power management of different types of renewable energy source is controlled by multiport DC-DC
converter. In this each port of the converter is connected with controller switch to control the source input of converter. This is
reduces the turn off switching losses by soft switching. The high frequency switches are used to control the power flow. This
converter is proposed to control the hybrid energy generating system, with the ability of bidirectional power flow between battery
and load. The diode bridge rectifier is applicable for high switching frequency operation with realizable component compare with
existing converter. The efficiency of the converter is verified through MATLAB simulation. The operation and design performance
is explained briefly. The proposed converter has reliability operate simultaneous power generation from different renewable
energy source. Fuzzy controller controls the direction of power flow and load voltage of the converter.
Keywords: Isolator, high frequency link, soft switching, multiport converter, PV panel, wind turbine generator (WTG
A new closed loop AC to DC ĈUK converter is presented in this paper. The conventional ĈUK AC to DC converter has no feedback circuit. Thereby, the output voltage of the converter changes while changing the load. The proposed closed loop converter can regulate voltage with the variation of load over a wide range. Moreover, the power factor and Total Harmonic Distortion (THD) of the supply side current found quite satisfactory from this closed loop ĈUK converter. The converter operates in four steps with a different combination of voltage polarities and switching states. The feedback path consists of a voltage control loop and a current control loop. The closed loop ĈUK converter in this study is compared with the open loop version. Additionally, the comparison is made with the conventional converter of the same topology. The effectiveness in terms of power factor and THD of the proposed converter is verified using simulation results.
Integration of Unified Power Quality Controller with DGIJRST Journal
This paper proposes integrating a Unified Power Quality Controller (UPQC) with a distributed generator (DG). The UPQC consists of series and shunt inverters connected to a common DC link, and can compensate for power quality issues like voltage sags/swells, harmonics, and reactive power. Integrating a DG connected through a rectifier to the DC link allows the system to operate in two modes: interconnected mode where the DG supplies power to the source and load, and islanding mode where the DG only supplies the load during a source voltage interruption. Simulations show the integrated system can compensate for voltage sags and swells in both forward and reverse power flow modes between the DG and
A ZVS Interleaved Boost AC/DC Converter Using Super Capacitor Power for Hybri...IJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
Single Phase Matrix Converter for Input Power Factor Improvementiosrjce
IOSR Journal of Electrical and Electronics Engineering(IOSR-JEEE) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of electrical and electronics engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in electrical and electronics engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Voltage-current Double Loop Control Strategy for Magnetically Controllable Re...Kashif Mehmood
Voltage regulation depending on reactive power
compensation is the main feature of the AC power supply
system. Magnetically controllable reactors (MCR) are
becoming a growing demand for this purpose. The structure
and working principles of MCR are analysed in this paper
while a simulation model is established. The reactive power
compensation strategy based on a single loop voltage control
system (SLVCS) is presented and a double loop
voltage-current control system (DLVCCS) is proposed. A
comprehensive scenario is developed to mitigate reactive power
compensation by using the proposed controls. Simulation
results substantiate that proposed controls of MCR has a faster
response in comparison to the traditional control, and it
provides the least voltage variation at the line end. It also
shows that the proposed control on MCR meet the desired
objective of the voltage regulation and provides flexibility to ac
transmission system
Analysis of Variable Speed PFC Chopper FED BLDC Motor DriveIJPEDS-IAES
This paper provides the detailed analysis of the DC-DC chopper fed Brushless DC motor drive used for low-power applications. The various methods used to improve the power quality at the ac mains with lesser number of components are discussed. The most effective method of power quality improvement is also simulated using MATLAB Simulink. Improved method of speed control by controlling the dc link voltage of Voltage Source Inverter is also discussed with reduced switching losses. The continuous and discontinuous modes of operation of the converters are also discussed based on the improvement in power quality. The performance of the most effective solution is simulated in MATLAB Simulink environment and the obtained results are presented.
This document discusses optimizing the energy production of an autonomous photovoltaic (PV) system with a simple charge regulator. The study determines the optimal open circuit voltage range of the PV field for 12V and 24V storage systems. Mathematical models are developed for PV modules, storage batteries, and charge regulators. Simulation results show that a PV field's open circuit voltage between 16-23V optimizes energy production for a 12V system, and between 34-43V for a 24V system, under standard test conditions. The optimal voltage ensures the intersection point between the PV and battery voltage-current characteristics is near the PV module's maximum power point.
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.
Comparison of an Isolated bidirectional Dc-Dc converter with and without a Fl...IOSR Journals
This document compares an isolated bidirectional DC-DC converter with and without a flyback snubber through simulation and hardware implementation. It begins with an introduction to isolated bidirectional converters and the problem of voltage spikes caused by transformer leakage inductance. It then describes the operation and components of the converter both with and without a flyback snubber. Simulation results show that the flyback snubber reduces voltage spikes by 78-80% by clamping the voltage. Hardware results for boost mode operation with a flyback snubber are also presented and agree with simulation.
This document summarizes a grid-connected photovoltaic power system that uses a boost-half-bridge converter. The system aims to efficiently transfer power from a solar PV array to the electric grid. It consists of two main stages - a boost-half-bridge DC-DC converter that steps up the low-voltage solar output, and a full-bridge inverter that feeds a sinusoidal current into the grid via an LCL filter. The boost-half-bridge converter provides galvanic isolation and a high step-up ratio with minimal components. Maximum power point tracking is performed to optimize solar energy extraction while limiting transient effects on efficiency.
This document summarizes a research paper that proposes and evaluates a novel interleaved ZCS boost DC-DC converter topology for photovoltaic interfaces. The converter uses two quasi-resonant switch blocks and lossless snubbers to achieve soft switching. Simulation results show the converter achieves reduced voltage and current ripple compared to conventional designs. A dual loop control scheme with an outer voltage loop and inner current loop is used to regulate the output. Coupling inductors between converter cells further improve transient response and reduce ripple. The proposed converter design and control scheme effectively interfaces photovoltaic systems with loads.
Photovoltaic System with SEPIC Converter Controlled by the Fuzzy LogicIAES-IJPEDS
In this work, a fuzzy logic controller is used to control the output voltage of a
photovoltaic system with a DC-DC converter; type Single Ended Primary
Inductor Converter (SEPIC). The system is designed for 210 W solar
photovoltaic (SCHOTT 210) panel and to feed an average demand of 78 W.
This system includes solar panels, SEPIC converter and fuzzy logic
controller. The SEPIC converter provides a constant DC bus voltage and its
duty cycle controlled by the fuzzy logic controller which is needed to
improve PV panel’s utilization efficiency. A fuzzy logic controller (FLC) is
also used to generate the PWM signal for the SEPIC converter.
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.
Analysis and simulation of even-level quasi-Z-source inverterIJECEIAES
This research proposes a seven-level inverter with quasi-Z-source boost converters. The proposed topology employs a packed U-cell asymmetrical type multilevel inverter along with front-end quasi-Z-source networks. The quasi networks provide high gain compared to a conventional boost converter. This topology is the most suitable for photovoltaic multi-string applications. The proposed topology has the potential to supply both the alternating current (AC) and direct current (DC) type load. The inverter structure has a lower number of active switches which helps in the reduction of losses and improvement in efficiency. In this paper, the operation principle of a quasi-network and inverter circuit are explained in detail. In addition, the simulation results for various modulation indices are presented. In the MATLAB/Simulink environment, the architecture is proposed by using gated sinusoidal “Pulse width modulation”.
Bidirectional full bridge dc-dc converter with flyback snubber for photovolta...IAEME Publication
This document describes a bidirectional full-bridge DC-DC converter with a flyback snubber circuit for photovoltaic applications. The converter allows for stepped-up voltage from a solar cell to charge a battery. It uses a current-fed full-bridge on the low voltage side and a voltage-fed bridge on the high voltage side, with an isolation transformer in between. A flyback snubber is used to clamp voltage spikes caused by current differences, reducing stress on the active switches. Simulation results show the converter successfully steps up 6V solar output to over 15V for battery charging. The flyback snubber regulates voltages while improving reliability.
This document summarizes a research paper on a bidirectional DC-DC converter with a Z-source network. The proposed converter aims to increase the output voltage level and regulation range compared to traditional bidirectional converters. It uses a fully bridge symmetrical circuit configuration with voltage and current sources. Simulation results using MATLAB show the converter can reduce current stress and improve efficiency for applications in hybrid electric vehicles and renewable energy systems. Key aspects analyzed include the converter's operating principles, voltage regulation model, and simulation circuit and results demonstrating operation in forward and reverse modes.
1) A single-phase matrix converter topology is presented that can synthesize a lower or higher DC output voltage from a given AC supply voltage. It uses an active pulse width modulation technique to maintain a continuous, sinusoidal input current that is in phase with the supply voltage, improving the input power factor.
2) Conventional rectifiers draw discontinuous current with high harmonics, resulting in poor power quality. The proposed single-phase matrix converter acting as a rectifier with active PWM can suppress harmonic current drawn by the rectifier load.
3) Simulation results show that for boost and buck rectification using the proposed single-phase matrix converter with active PWM technique, the supply current is sinusoidal and in phase
A Modern Technique of Deduction in Leakage Current in Resonant Bi-directional...IJMTST Journal
This Paper Presents A whole New resonant twin active bridge(DAB) topology, that uses a tuned inductor-capacitor-inductor(LCL) network. As compared to ancient DAB topologies, the planned topologies significantly reduced the bridge current, lowering every physical phenomenon and alter losses and conjointly VA rating associated with the bridges. The performance of the DAB is investigated using a mathematical model at a lower place varied operational conditions. Experiment results of a model is reduced the outflow current of the circuit. are presented with discussion to demonstrate the improved performance of the LCL DAB topology. Result clearly that the planned DAB Topology provide higher efficiency over an oversized vary of every input voltage and as compared to ancient DAB topology
This document summarizes a research paper that proposes a 7-level multilevel inverter based electric spring with a resonant switched capacitor converter to enhance voltage regulation in a distribution system. The electric spring uses demand side management to maintain constant voltage for critical loads during voltage variations from distributed generation sources. The proposed topology reduces component count and maintains balanced voltages across input capacitors compared to previous electric spring implementations. Simulations test the proposed topology under voltage sag and swell conditions and analyze results based on total harmonic distortion in the critical load voltage.
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.
IRJET- A Systematic Approach to Design Single Phase Transformer Less Inve...IRJET Journal
This document presents a new transformerless inverter topology for grid-tied photovoltaic systems that can control reactive power. The topology aims to improve efficiency by utilizing MOSFET switches and maintains a constant common mode voltage to reduce leakage currents. It was tested with a 1 kW prototype and experimental results showed it can inject reactive power into the grid without additional current distortion or leakage. The control scheme for the topology is also analyzed, demonstrating it can effectively respond to changes in active power reference.
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.
The document discusses the use of solid state transformers (SST) in wind energy systems. SST can effectively replace conventional transformers and reactive power compensators, increasing the flexibility of wind energy systems. SST integrate rectification, isolation, and inversion stages to provide voltage conversion as well as reactive and active power compensation. The document also describes how SST can be interfaced with wind energy systems to provide benefits such as power factor control, fast isolation during faults, and regulation of both AC and DC loads.
A three-phase bidirectional isolated dc-dc converter consists of two six-pulse two-level active converters that enable bidirectional power flow by introducing a lag phase-shift angle of one converter with respect to the other converter. This paper explains the operating modes of a three-phase bidirectional isolated dc-dc converter in detail, taking into account the transfer of energy between the dc voltage sources and high-frequency ac inductances in the three-phase bidirectional isolated dc-dc converter. The power flow of the dc-dc converter is also examined based on the operating modes.
Coupled Inductor Based High Step-Up DC-DC Converter for Multi Input PV SystemIJERA Editor
With the shortage of the energy and ever increasing of the oil price, research on the renewable and green energy
sources, especially the solar arrays and the fuel cells, becomes more and more important. How to achieve high
step-up and high efficiency DC/DC converters is the major consideration in the renewable power applications
due to the low voltage of PV arrays and fuel cells. In this paper a coupled inductor dc-dc converter for photovoltaic
system is proposed. The circuit configuration of the proposed converter is very simple. Thus, the
proposed converter has higher step-up and step-down voltage gains than the conventional bidirectional dc–dc
boost/buck converter. Under same electric specifications for the proposed converter and the conventional
bidirectional boost/buck converter, the average value of the switch current in the proposed converter is less than
the conventional bidirectional boost/buck converter. The operating principles have been applied to multi input
photovoltaic system and outputs have been observed.
Filter Based Solar Power Generation System with a Seven Level InverterIJMTST Journal
This paper proposes a new solar power generation system, which is composed of a DC/DC power converter and a new seven-level inverter. The DC/DC power converter integrates a DC-DC boost converter and a transformer to convert the output voltage of the solar cell array into two independent voltage sources with multiple relationships. This new seven-level inverter is configured using a capacitor selection circuit and a full-bridge power converter, connected in cascade. The capacitor selection circuit converts the two output voltage sources of DC-DC power converter into a three-level DC voltage and the full- bridge power converter further converts this three- level DC voltage into a seven-level AC voltage. In this way, the proposed solar power generation system generates a sinusoidal output current that is in phase with the utility voltage and is fed into the utility. The salient features of the proposed seven-level inverter are that only six power electronic switches are used and only one power electronic switch is switched at high frequency at any time. A prototype is developed and tested to verify the performance of this proposed solar power generation system.
IJERD (www.ijerd.com) International Journal of Engineering Research and Devel...IJERD Editor
This document summarizes a research paper that proposes a soft-switching boost converter with an auxiliary resonant circuit (SARC) for improving the efficiency of photovoltaic (PV) energy conversion systems. The converter is designed to boost the variable output voltage of a solar module. Simulation and experimental results confirm the converter's operational principles and soft-switching performance. The converter achieves zero-voltage switching and zero-current switching, reducing switching losses compared to conventional hard-switching converters. The design procedure and component values for the resonant inductor and capacitor in the SARC are also described.
Harnessing WebAssembly for Real-time Stateless Streaming PipelinesChristina Lin
Traditionally, dealing with real-time data pipelines has involved significant overhead, even for straightforward tasks like data transformation or masking. However, in this talk, we’ll venture into the dynamic realm of WebAssembly (WASM) and discover how it can revolutionize the creation of stateless streaming pipelines within a Kafka (Redpanda) broker. These pipelines are adept at managing low-latency, high-data-volume scenarios.
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.
A SYSTEMATIC RISK ASSESSMENT APPROACH FOR SECURING THE SMART IRRIGATION SYSTEMSIJNSA Journal
The smart irrigation system represents an innovative approach to optimize water usage in agricultural and landscaping practices. The integration of cutting-edge technologies, including sensors, actuators, and data analysis, empowers this system to provide accurate monitoring and control of irrigation processes by leveraging real-time environmental conditions. The main objective of a smart irrigation system is to optimize water efficiency, minimize expenses, and foster the adoption of sustainable water management methods. This paper conducts a systematic risk assessment by exploring the key components/assets and their functionalities in the smart irrigation system. The crucial role of sensors in gathering data on soil moisture, weather patterns, and plant well-being is emphasized in this system. These sensors enable intelligent decision-making in irrigation scheduling and water distribution, leading to enhanced water efficiency and sustainable water management practices. Actuators enable automated control of irrigation devices, ensuring precise and targeted water delivery to plants. Additionally, the paper addresses the potential threat and vulnerabilities associated with smart irrigation systems. It discusses limitations of the system, such as power constraints and computational capabilities, and calculates the potential security risks. The paper suggests possible risk treatment methods for effective secure system operation. In conclusion, the paper emphasizes the significant benefits of implementing smart irrigation systems, including improved water conservation, increased crop yield, and reduced environmental impact. Additionally, based on the security analysis conducted, the paper recommends the implementation of countermeasures and security approaches to address vulnerabilities and ensure the integrity and reliability of the system. By incorporating these measures, smart irrigation technology can revolutionize water management practices in agriculture, promoting sustainability, resource efficiency, and safeguarding against potential security threats.
Understanding Inductive Bias in Machine LearningSUTEJAS
This presentation explores the concept of inductive bias in machine learning. It explains how algorithms come with built-in assumptions and preferences that guide the learning process. You'll learn about the different types of inductive bias and how they can impact the performance and generalizability of machine learning models.
The presentation also covers the positive and negative aspects of inductive bias, along with strategies for mitigating potential drawbacks. We'll explore examples of how bias manifests in algorithms like neural networks and decision trees.
By understanding inductive bias, you can gain valuable insights into how machine learning models work and make informed decisions when building and deploying them.
Embedded machine learning-based road conditions and driving behavior monitoringIJECEIAES
Car accident rates have increased in recent years, resulting in losses in human lives, properties, and other financial costs. An embedded machine learning-based system is developed to address this critical issue. The system can monitor road conditions, detect driving patterns, and identify aggressive driving behaviors. The system is based on neural networks trained on a comprehensive dataset of driving events, driving styles, and road conditions. The system effectively detects potential risks and helps mitigate the frequency and impact of accidents. The primary goal is to ensure the safety of drivers and vehicles. Collecting data involved gathering information on three key road events: normal street and normal drive, speed bumps, circular yellow speed bumps, and three aggressive driving actions: sudden start, sudden stop, and sudden entry. The gathered data is processed and analyzed using a machine learning system designed for limited power and memory devices. The developed system resulted in 91.9% accuracy, 93.6% precision, and 92% recall. The achieved inference time on an Arduino Nano 33 BLE Sense with a 32-bit CPU running at 64 MHz is 34 ms and requires 2.6 kB peak RAM and 139.9 kB program flash memory, making it suitable for resource-constrained embedded systems.
Presentation of IEEE Slovenia CIS (Computational Intelligence Society) Chapte...University of Maribor
Slides from talk presenting:
Aleš Zamuda: Presentation of IEEE Slovenia CIS (Computational Intelligence Society) Chapter and Networking.
Presentation at IcETRAN 2024 session:
"Inter-Society Networking Panel GRSS/MTT-S/CIS
Panel Session: Promoting Connection and Cooperation"
IEEE Slovenia GRSS
IEEE Serbia and Montenegro MTT-S
IEEE Slovenia CIS
11TH INTERNATIONAL CONFERENCE ON ELECTRICAL, ELECTRONIC AND COMPUTING ENGINEERING
3-6 June 2024, Niš, Serbia
International Conference on NLP, Artificial Intelligence, Machine Learning an...gerogepatton
International Conference on NLP, Artificial Intelligence, Machine Learning and Applications (NLAIM 2024) offers a premier global platform for exchanging insights and findings in the theory, methodology, and applications of NLP, Artificial Intelligence, Machine Learning, and their applications. The conference seeks substantial contributions across all key domains of NLP, Artificial Intelligence, Machine Learning, and their practical applications, aiming to foster both theoretical advancements and real-world implementations. With a focus on facilitating collaboration between researchers and practitioners from academia and industry, the conference serves as a nexus for sharing the latest developments in the field.
2. 4668 IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 27, NO. 11, NOVEMBER 2012
Fig. 1. Typical application of BDC for power distribution in microgrid [11].
Fig. 2. Typical configuration of IBDC.
In TPS control [14]–[16], [20], the cross-connected switch
pairs in both H-bridges (H1 and H2 ) are switched in turn to gen-erate
phase-shifted transition square waves to the transformer’s
primary and secondary sides. And the corresponding phase shift
changes the voltage across the transformer’s leakage inductor to
manipulate the power flowdirection and magnitude. This control
method is attracting more and more attention due to its advan-tages
such as small inertia, high dynamic performance, easy to
realize soft-switching control, and so on. But in this method, the
control of the power flow is dependent on transformer’s leak-age
inductor that result in great circulating power and current
stress when the value of V1 /nV2 deviate far from 1, where n is
turns’ ratio of the transformer. And then, the loss in power de-vices
and magnetic components is increased and the efficiency
of converter is reduced. In order to improve the performance of
the IBDC, various control methods were explored [21]–[25]. In
some of these studies [21], [22], the duty ratio of the driving
signals of each semiconductor device is variable, and should be
calculated online, that increases the complexity of the control.
Some studies are focused on how to extend the soft-switching
range [23] or eliminate reactive power [24], the detailed anal-ysis
of steady characteristics is not conducted. In [25], a novel
phase-shift dual-half-bridge converter with an adaptive inductor
was proposed. It utilizes an adaptive inductor as the commuta-tion
inductor to adapt to the change of the output power, which
results in strict requirements of the coiling method of inductor
and the complexity of the control. And it is mainly improve-ment
of hardware design; the control method of the proposed
converter is still TPS control.
In view of the study situation mentioned above, this paper
points out a phenomenon of power backflowin traditional phase-shift
control, and analyzes the effects which backflow power act
Fig. 3. Equivalent circuit of phase-shift control.
on power circulating flow and current stress. On this basis, the
paper presents a novel extended-phase-shift control of IBDC
for power distribution in microgrid. Different from the control
methods mentioned above, this method adds another degree of
freedom to the converter by adjusting the time sequence between
the driving signals of diagonal semiconductor switches, e.g.,
(S1, S4 ) in Fig. 2. It not only has smaller power circulating
flow and current stress, but also expands regulating range of
transmission power and enhances regulating flexibility.
II. PHENOMENON OF POWER BACKFLOW IN TRADITIONAL
PHASE-SHIFT CONTROL
In Fig. 2, we replace the transformer with T-type equivalent
circuit, and considering that the magnetizing inductance of the
transformer is much greater than its leakage inductance, the
magnetizing inductance can be considered as an open circuit.
Therefore, the converter in phase-shift control can be repre-sented
by a simplified scheme comprised of two square waves
voltage sources linked by an inductance L, as shown in Fig. 3.
In Fig. 3, L is the sum of the transformer leakage inductance
and that of the auxiliary inductor L1 , vh1 and vh2 are the equiv-alent
AC output voltages of H1 and H2 in V1 side, respectively,
vL and iL are the voltage and current of inductor L, respectively.
The power-flow direction and magnitude can simply be con-trolled
by adjusting the phase shift between vh1 and vh2. Here
we take the forward power flow (from V1 to V2 ) as an example
to analyze the main operation principle of TPS control.
The main waveforms of IBDC in TPS control are shown
in Fig. 4, where pin is the transient waveform of transmission
power, Ths is a half switching period, and D is the phase-shift
ratio between the primary and secondary voltages of the isola-tion
transformer, where 0 ≤ D ≤ 1.Andwe assume V1 ≥ nV2 in
Fig. 4, the other condition V1 < nV2 can be analyzed similarly.
Because vh1 and vh2 are both square wave AC voltages and their
3. ZHAO et al.: EXTENDED-PHASE-SHIFT CONTROL OF ISOLATED BIDIRECTIONAL DC–DC CONVERTER 4669
Fig. 4. Waveforms of IBDC in TPS control.
interaction is through the inductor L, so the phase of the primary
current is not always the same as the primary voltage. As can
be seen from Fig. 4, iL is of the opposite phase from vh1 for an
interval of t = t0 ∼ t
0 and t = t2 ∼ t
2 , that is a portion of the
power delivered to the V2 side in one switching period, while
the other portion is sent back to the primary voltage source V1 .
We defined it as backflow power, which is the dark-shaded area
in Fig. 4. For a given transmission power, with the increase of
the backflow power, the forward power also increases to com-pensate
the loss caused by backflow power. Then the circulating
power and current stress are increased, which result in great loss
in power devices and magnetic components and low efficiency
of converter [16], [19]–[23]. In Section IV, we will establish a
mathematical model to analyze it.
III. OPERATION PRINCIPLE OF EXTENDED-PHASE-SHIFT
CONTROL
A. Extended-Phase-Shift Control
In order to significantly decrease the backflow power of the
converter, vh1 should not be confined to square waveforms with
Fig. 5. Waveforms of IBDC in EPS control.
50% duty ratio. For example, if S1 and S4 do not have the same
driving signal but have a phase-shift ratio of D1, as shown in
Fig. 5, the transformer primary voltage will emerge as a three-level
instead of the traditional two-level. Then the behaviors
of iL will also be changed: the backflow-appearance time (t =
t0 ∼ t
0 and t = t2 ∼ t
2 ) in Fig. 4 are divided into two intervals
(t = t0∼t1 , t = t1 ∼ t
1 and t = t3∼t4 , t = t4 ∼ t
4) in Fig. 5,
respectively. And the transformer primary voltage vh1 = 0, i.e.,
backflow power is 0, when t = t0∼t1 and t = t3∼t4. So the
backflow power is decreased for a given transmission power. In
the reverse power flow, we just need to exchange the operating
states of the H-bridges H1 and H2 .
In Fig. 5, D1 is the phase-shift ratio between the driving sig-nals
of S1 and S4 or S 2 and S3 in H-bridge H1 , we defined its
inner phase-shift ratio, where 0 ≤ D1 ≤ 1. D2 is the phase-shift
4. 4670 IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 27, NO. 11, NOVEMBER 2012
Fig. 6. Operation modes of IBDC in EPS control. (a) Mode 1. (b) Mode 2. (c) Mode 3. (d) Mode 4. (e) Mode 5. (f) Mode 6. (g) Mode 7. (h) Mode 8.
ratio between the primary and secondary voltages of the isola-tion
transformer, we defined its outer phase-shift ratio, where
0 ≤ D2 ≤ 1 and 0 ≤ D1+D2 ≤ 1. In fact, compared to the
TPS control, there is not only the outer phase-shift ratio but also
the inner phase-shift ratio in the proposed EPS control, which
will decrease the current stress, expands regulating range of
transmission power and enhances regulating flexibility.
B. Operation Modes of IBDC in Extended-Phase-Shift Control
To simplify the process of the analysis, we assume that the
converter has reached steady operation states. From Fig. 5, the
switching cycle can be divided into eight operation modes which
are explained as follows:
1) Mode 1 (t0–t1 ): Fig. 6(a) shows the equivalent circuit for the
mode 1. Just before t0, S2 and S3 are conducting. The current iL
is in negative direction. At t0, S3 is turned OFF and S4 is turned
ON at zero current, and D4 starts to conduct. On the secondary
side, the current is carried from L to V2 by M2 and M3. The
voltage across L is clamped at nV2 , and the current iL decreases
linearly. This mode ends up when S2 is turned OFF. During this
mode, the current of L is
iL (t) = iL (t0) + nV2
L
(t − t0 ). (1)
2) Mode 2 (t1–t
1 ): Fig. 6(b) shows the equivalent circuit for
mode 2. If current iL is still in negative direction at t1 then at
t1, S2 is turned OFF and S1 is turned ON at zero current, iL
is carried from L to V1 by D1 and D4 . On the secondary side,
the current is carried from L to V2 by M2 and M3 . The voltage
across L is clamped at V1+nV2 , and iL still decreases linearly.
This mode ends up with iL decreasing to zero. During this mode,
iL is
iL (t) = iL (t1) + V1 + nV2
L
(t − t1 ). (2)
5. ZHAO et al.: EXTENDED-PHASE-SHIFT CONTROL OF ISOLATED BIDIRECTIONAL DC–DC CONVERTER 4671
3) Mode 3 (t
1–t2 ): Fig. 6(c) shows the equivalent circuit for
the mode 3. At t
1 , the polarity of iL changes from negative to
positive. And because the driving signals of S1, S4, Q2 , and
Q3 are already on, so S1, S4, Q2 , and Q3 start to conduct.
The voltage across L is clamped at V1 + nV2 , and iL increases
linearly. This mode ends up when Q2 and Q3 are turned OFF.
During this mode, iL is the same with (2).
4) Mode 4 (t2 – t3 ): Fig. 6(d) shows the equivalent circuit for
the mode 4. At t2, Q2 and Q3 are turned off and Q1 and Q4
are turned on at zero current. M1 and M4 start to conduct. The
voltage across L is clamped at V1–nV2 , and iL still increases
linearly due to V1 ≥ nV2 . This mode ends up when S4 is turned
OFF. During this mode, iL is
iL (t) = iL (t2) + V1 − nV2
L
(t − t2 ). (3)
5) Mode 5 (t3 – t4 ): Fig. 6(e) shows the equivalent circuit for
mode 5. At t3, S4 is turned OFF and S3 is turned ON at zero
current, D3 starts to conduct. On the secondary side, the current
is carried from L to V2 by M1 and M4 . The voltage across L
is clamped at –nV2 , and the current iL decreases linearly. This
mode ends up when S1 is turned OFF. During this mode, the
current of L is
iL (t) = iL (t3) +
−nV2
L
(t − t3 ). (4)
6) Mode 6 (t4 – t
4 ): Fig. 6(f) shows the equivalent circuit for
mode 6. If current iL is still in positive direction at t4 , then at
t4, S2 is turned OFF and S1 is turned ON at zero current, iL
is carried from L to V1 by D2 and D3 . On the secondary side,
the current is carried from L to V2 by M1 and M4 . The voltage
across L is clamped at –V1–nV2 , and iL still decreases linearly.
This mode ends up with iL decreasing to zero. During this mode,
iL is
iL (t) = iL (t4) +
−V1 − nV2
L
(t − t4 ). (5)
7) Mode 7 (t
4–t5 ): Fig. 6(g) shows the equivalent circuit for
the mode 7. At t
4 , the polarity of iL changes from positive to
negative. And, because the driving signals of S2, S3, Q1 , and
Q4 are already ON, so S2, S3, Q1 , and Q4 start to conduct.
The voltage across L is clamped at –V1–nV2 , and iL increases
linearly. This mode ends up when Q1 and Q4 are turned OFF.
During this mode, iL is the same with (5).
8) Mode 8 (t5 – t6 ): Fig. 6(h) shows the equivalent circuit for
the mode 8. At t5, Q1 and Q4 are turned OFF and Q2 and Q3
are turned ON at zero current. M2 and M3 start to conduct. The
voltage across L is clamped at –V1+nV2 , and iL still increases
linearly due to V1 ≥ nV2 . This mode ends up when S3 is turned
OFF. During this mode, iL is
iL (t) = iL (t5) +
−V1 + nV2
L
(t − t5 ). (6)
According to the above analysis, the transformer primary
voltage vh1 = 0, and there is no backflow power in modes 1
and 5. So the whole backflow power is decreased for a given
transmission power. In fact, if iL has dropped to zero before t1
or t4 , then the backflow power will be eliminated, as shown in
Fig. 7(a). In this case, modes 2 and 6 in Fig. 6 will be replaced
by mode 2 and 6 in Fig. 7(b) and (c), respectively.
9) Mode 2 (t
1–t1 ): Fig. 7(b) shows the equivalent circuit
for mode 2. At t
1 , the polarity of iL changes from negative
to positive. And because the driving signals of S2, S4, Q2 , and
Q3 are already ON, so D2, S4, Q2 , and Q3 start to conduct.
The voltage across L is clamped at nV2 , and iL still increases
linearly. This mode ends up when S2 is turned OFF. During this
mode, iL is the same with (1).
10) Mode 6 (t
4–t4 ): Fig. 7(c) shows the equivalent circuit
for mode 6. At t
4 , the polarity of iL changes from positive to
negative. And because the driving signals of S1, S3, Q1 , and
Q4 are already ON, so D1, S3, Q1 , and Q4 start to conduct.
The voltage across L is clamped at –nV2 , and iL still increases
linearly. This mode ends up when S1 is turned OFF. During this
mode, iL is the same with (4).
IV. ANALYSIS AND COMPARISONS OF TPS AND EPS CONTROL
A. Low-Frequency Average Model
According to the above analysis, assuming t0 = 0, then we
have t1 = D1Ths, t2 = D2Ths, t3 = Ths, t4 = Ths+D1Ths, t5 =
Ths+D2Ths, and t6 = 2Ths. The average current of the inductors
over one switching period (2Ths) should be zero in steady state;
thus from (1) to (6), we can derive
iL (t0) = − nV2
4fsL
[k(1 − D1) + (2D1 + 2D2 − 1)] (7)
iL (t1) = − nV2
4fsL
[k(1 − D1) + (2D2 − 1)] (8)
iL (t2) = nV2
4fsL
[k(2D2 + D1 − 1) + 1] (9)
where fs = 1/(2Ths) is switching frequency, k = V1/nV2 is the
voltage conversion ratio, and we assume k ≥ 1 in the paper,
the other condition k 1 can be analyzed similarity. When the
power flows from V1 to V2 , the current stress of converter under
EPS control is
max = |iL (t0 )| = nV2
i
4fsL
[k(1 − D1) + (2D1 + 2D2 − 1)].
(10)
The transmission power is
P
=
1
Ths
Th s
0
vh1iL (t)dt
= nV1V2
2fsL
D2(1 − D2) +
. (11)
1
2D1(1 − D1 − 2D2 )
6. 4672 IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 27, NO. 11, NOVEMBER 2012
Fig. 7. (a) Waveforms of IBDC in EPS control when the backflow power is zero. (b) Mode 2 of IBDC in EPS control when the backflow power is zero. (c)
Mode 6 of IBDC in EPS control when the backflow power is zero.
The backflow power is
P
bf =
1
Ths
t
1
t1
vh1 |iL (t)|dt
= nV1V2 [k(1 − D1) + (2D2 − 1)]2
16fsL(k + 1)
(12)
where iL (t1 ) 0, from (8), we have
k
1 − 2D2
1 − D1
. (13)
When k ≤ (1–2D2 )/(1–D1 ), the backflow power is zero. In (7)–
(13), the constraints are k ≥ 1, 0 ≤ D1 ≤ 1, 0 ≤ D2 ≤1, and
0 ≤ D1+D2 ≤ 1. Similarly, from Fig. 4, the current stress of
converter under TPS control is
imax = nV2
4fsL
(2D − 1 + k). (14)
The transmission power is
P = nV1V2
2fsL
D(1 − D). (15)
The backflow power is
Pbf = nV1V2 [k + (2D − 1)]2
16fsL(k + 1) . (16)
In (14)–(16), the constraints are k ≥ 1 and 0 ≤ D ≤ 1.
Theoretically, when the load is set as resistance R, from (11),
we can derive
V2 = nV1R
2fsL
D2(1 − D2) +
1
2D1(1 − D1 − 2D2 )
. (17)
With the variation of D1 and D2, we have
0 ≤ V2 ≤ nV1R
8fsL
. (18)
Similarly, from (15), the output voltage range in the TPS control
can be achieved. In fact, the output voltage range in the EPS
control is the same as that in the TPS control. And its main
benefit lies in that the power circulating flow and current stress
are both reduced for a given output power; therefore, it leads
to the improvement of the converter’s overall efficiency. Theory
and experiment analysis of the paper are centering on these
special characteristics of EPS control as well.
B. Comparative Analysis of Transmission Power
For the convenience of analysis, the unified transmission
power p and p are defined as
⎧⎪⎪⎨
⎪⎪⎩
p = P
PN
= 4D2(1 − D2) + 2D1(1 − D1 − 2D2 )
p = P
PN
= 4D(1 − D)
(19)
7. ZHAO et al.: EXTENDED-PHASE-SHIFT CONTROL OF ISOLATED BIDIRECTIONAL DC–DC CONVERTER 4673
Fig. 8. Relation curves of the unified transmission power p with D1 and D2 . (a) 3-D curves. (b) 2-D curves.
where
PN = nV1V2
8fsL
. (20)
When taking that the outer phase-shift ratio (D2) in EPS
control is equal to the phase-shift ratio (D) in TPS control, the
3-D curves of the unified transmission power p and p varied with
D1 andD2 shown in Fig. 8(a). As can be seen from Fig. 8(a), with
different D1 , p will be different with p. And the EPS control
can achieve larger transmission power than the TPS does when
0 ≤ D2 0.5. In fact, from (19), we can derive
p
max = 1− (1 − 2D2 )2
2
(21)
where 0 ≤ D2 0.5 and D1 = (1-2D2 )/2.
p
max = 4D2(1 − D2 ) (22)
where 0.5 ≤ D2 1 and D1 = 0.
p
min = 2D2(1 − D2 ) (23)
where D1 = 1-D2 .
From (21) to (23), Fig. 8(a) can be converted to a 2-D picture,
as shown in Fig. 8(b). The dashed line is the regulating curve
of transmission power in TPS control, and the dark-shaded area
is the regulating area of transmission power in EPS control.
From Fig. 8(b), due to the addition of D1 , the regulating range
of transmission power is changed from the single curve to the
2-D area. With the same outer phase-shift ratio (D2 = D), the
EPS control offers wider power transmission range than the TPS
control does, and the maximum value is determined by (21) and
(22) while the minimum value is determined by (23). Due to the
addition of D1 , the regulating flexibility of transmission power
is also enhanced.
Considering that the basic prerequisite for comparative analy-sis
of backflow power and current stress is that the transmission
power of TPS and EPS control are the same. In the follow-ing
analysis, we take operating points A/A4 , B/B3 , and C/C2 as
characteristic points of TPS control in different operating ar-eas,
where A(D = 1/8), A4 (D = 7/8), B(D = (2 − 21/2)/4),
B3 (D = (2+21/2)/4), C(D = 1/4), and C2 (D = 3/4), then the
characteristic points of EPS control are A1 /A2 /A3 , B1 /B2 , and
C1 .
C. Comparative Analysis of Backflow Power
Considering the relationship between the backflow power
and the transmission power, the unified backflow power Mbf
and M
bf are defined as
M
bf =
P
bf
PN
=
[k(1 − D1) + (2D2 − 1)]2
2(k + 1)
(24)
Mbf = Pbf
PN
=
[k + (2D − 1)]2
2(k + 1) . (25)
The basic prerequisite for comparative analysis of backflow
power is that the transmission power of TPS and EPS control
are the same. From (11) and (15), we have
4D(1 − D) = 4D2(1 − D2) + 2D1(1 − D1 − 2D2 ). (26)
With the specified value of D1 and D2 in EPS control, the
phase-shift ratio D in TPS control can be obtained
D=
⎧⎪⎪⎨
⎪⎪⎩
D =
1 −
1 − 4D2(1 − D2 ) − 2D1(1 − D1 − 2D2 )
2
D =
1 +
1 − 4D2(1 − D2 ) − 2D1(1 − D1 − 2D2 )
2
.
(27)
Using (24), (25), and (27), and assuming k = 5, the 3-D curve of
the unified backflow power varied with D1 and D2 can be shown
in Fig. 9. As can be seen from Fig. 9, the backflow power in
TPS and EPS control are the same when D1 = 0. And due to the
addition of D1 , with the same transmission power, the backflow
power in TPS control is larger than that in EPS control, and the
condition of D = D generates larger backflow power than the
condition of D = D does.
The contour lines in Fig. 8(b) show that there are infinite
combinations of (D1 , D2 ) in EPS control for the same transmis-sion
power in TPS control. Considering the different qualities
of EPS control in different operating points, we will analyze the
8. 4674 IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 27, NO. 11, NOVEMBER 2012
Fig. 9. 3-D curves of the unified backflow power M
bf varied with D1 and
D2 .
optimal operating point of backflow power. From (26), we have
D1 =
⎧⎪⎪⎨
⎪⎪⎩
D1
=
1 − 2D2 −
2(1 − 2D)2 − (1 − 2D2 )2
2
D
1 =
1 − 2D2 +
2(1 − 2D)2 − (1 − 2D2 )2
2
.
(28)
For D
1 ≥ D1
, from (24), we have
M
bf (D
1
) ≥ M
bf (D
1 ). (29)
Substituting D1 = D
1 into (24), the function of M
bf and D2
can be obtained
M
bf min(D2 )
=
[k(1−
2(1 − 2D)2−(1 − 2D2 )2)+ 2(k + 2)D2 − 2]2
8(k + 1)
(30)
where |1–2D2| ≤ 21/2 |1–2D| and 0 ≤ D2 ≤ 1. Solving (30)
with constrained optimization methods, we can derive
1) when 0 ≤ D (2–21/2)/4
M
bf min(D2)=M
bf min(0) =
[k − 2 − k
2(1 − 2D)2 − 1]2
8(k + 1)
(31)
where
⎧⎨
⎩
D1 =
1 +
2(1 − 2D)2 − 1
2
D2 = 0
(32)
2) when (2–21/2)/4 ≤ D 1/2
M
bf min(D2) = M
bf min
1 −
√
2(1 − 2D)
2
=
√
2 − 1)k − 2 + 2(k + 2)D]2
[(
4(k + 1)
(33)
where
⎧⎪⎪⎨
⎪⎪⎩
D1 =
√
2(1 − 2D)
2
D2 =
1 −
√
2(1 − 2D)
2 .
(34)
In Fig. 8(b), we take operating points A, B, C, A1 /A2 /A3 , B1 /B2 ,
and C1 as characteristic points of TPS and EPS control in differ-ent
operating areas, from (19) to (21), and (26), we have: A1 (D2
= 0, D1 = (4+21/2)/8), A1
(D2 = 0, D1 = (4–21/2)/8), A2 (D2
= (4–21/2)/8, D1 = (4+21/2)/8), A3 (D2 = (4+21/2)/8, D1 =
(4–21/2)/8), B1 (D2 =0,D1 =1/2), B2 (D2 =1/2,D1 =1/2), and
C1 (D2 = (2–21/2)/4, D1 = 21/2/4). Fig. 10 shows the curves of
the unified backflow power varied with voltage conversion ratio
k in TPS and EPS control for the same transmission power.
D. Comparative Analysis of Current Stress
For the convenience of analysis, the unified current stress G
and G are defined as
G
= i
max
IN
= 2[k(1 − D1) + (2D1 + 2D2 − 1)] (35)
G = imax
IN
= 2(2D − 1 + k) (36)
where
IN = PN
V1
= nV2
8fsL
. (37)
Using (27), (35), and (36), and assuming k = 5, the 3-D curve
of the unified current stress varied with D1 and D2 as shown in
Fig. 11. As can be seen from Fig. 11, the current stress in TPS
and EPS control are the same when D1 = 0. And due to the
addition of D1 with the same transmission power, the current
stress in TPS control is larger than that in EPS control, and the
condition of D = D generates larger current stress than the
condition of D = D does.
Likewise, the optimal operating point of current stress can be
analyzed. For D
1 ≥ D1
, from (35), we have
9. G(D1
) ≤ G(D
1 ) k 2
G(D
1 ) ≤ G(D1
) k ≥ 2.
(38)
That is,
min(D2) =
G
⎧⎪⎪⎨
⎪⎪⎩
2(1 − 2D)2 − (1 − 2D2 )2
(k − 2)
+2kD2 +k k2
2(1 − 2D)2 − (1 − 2D2 )2
(2 − k)
+2kD2 +k k≥ 2
(39)
where |1–2D2| ≤ 21/2 |1–2D| and 0 ≤ D2 ≤ 1. Solving (39)
with constrained optimization methods, we can derive
1) when 0 ≤ D (2–21/2)/4
min(D2) =
G
2(1 − 2D)2 − 1 +k k2
(k − 2)
2(1 − 2D)2 − 1 +k k≥ 2
(2 − k)
(40)
10. ZHAO et al.: EXTENDED-PHASE-SHIFT CONTROL OF ISOLATED BIDIRECTIONAL DC–DC CONVERTER 4675
Fig. 10. Curves of the unified backflow power M
bf varied with voltage conversion ratio k. (a) A and A4 in TPS control and A1 , A
1 , A2, and A3 in EPS control.
(b) B and B3 in TPS control and B1 and B2 in EPS control. (c) C and C2 in TPS control and C1 in EPS control.
Fig. 11. 3-D curves of the unified current stress G varied with D1 and D2 .
where
⎧⎪⎪⎪⎪⎨
⎪⎪⎪⎪⎩
D1 =
⎧⎪⎪⎨
⎪⎪⎩
1 −
2(1 − 2D)2 − 1
2 k 2
1 +
2(1 − 2D)2 − 1
2 k ≥ 2
D2 = 0.
(41)
According to (32) and (41), when k≥2, the optimal operating
points of backflow power and current stress are the same. From
(36) and (40), we can derive
11. G ≤ G
min k k0
G
min
≤G k≥ k0
(42)
k0 = 2− 1 +
2(1 − 2D)2 − 1
2(1 − D)
(43)
2) when (2–21/2)/4 ≤ D 1/2
min(D2) = k(2
G
√
2D + 2 −
√
2) (44)
where
⎧⎪⎪⎨
⎪⎪⎩
D1 =
√
2(1 − 2D)
2
D2 =
1 −
√
2(1 − 2D)
2 .
(45)
From (36) and (44), we can derive
12. G ≤ G
min k k0
G
min
≤G k≥ k0
(46)
where
k0 =
√
2. (47)
According to the above analysis, when k ≥ k0 , the current stress
in EPS control is less than that in TPS control. Likewise, we take
operating points A, B, C, A1 /A2 /A3 , B1 /B2 , and C1 as character-istic
points of TPS and EPS control in different operating areas.
Then the curves of the unified current stress varied with voltage
conversion ratio k for the same transmission power shown in
Fig. 12.
As can be seen from Fig. 12, in all operating areas, the current
stress increases with the increase of voltage conversion ratio k.
The EPS control can take different operating points to ensure
that the current stress is less than the TPS control when k ≥ k0 ,
and the minimum value is obtained at A1 , B1 , and C1 , which
agrees well with the aforementioned theoretical analysis.
V. EXPERIMENTAL RESULTS
In order to verify the aforementioned analysis, a laboratory
prototype is constructed based on TMS320F2812 DSP. And the
main parameters of converter are shown in Table I.
In order to verify the power regulating capacity of EPS con-trol,
the input voltage and the output load are specified as 220V
and 6 Ω, respectively. Fig. 13 shows the curves of the transmis-sion
power varied with D1 and D2 . As can be seen from Fig. 13,
in EPS control, the transmission power can be regulated both by
D1 and D2 , and due to the addition of D1 , the regulating range
13. 4676 IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 27, NO. 11, NOVEMBER 2012
Fig. 12. Curves of the unified current stress G varied with voltage conversion ratio k. (a) A and A4 in TPS control and A1 , A1
, A2 , and A3 in EPS control. (b) B
and B3 in TPS control and B1 and B2 in EPS control. (c) C and C2 in TPS control and C1 in EPS control.
Fig. 13. Curves of the transmission power varied with D1 and D2 . (a) Curves of the transmission power varied with D1 when D2 is specified. (b) Curves of the
transmission power varied with D2 when D1 is specified.
TABLE I
MAIN PARAMETERS OF PROTOTYPE
of transmission power is changed from the single curve to the
2-D area.With the same outer phase-shift ratio (D2 = D 0.5),
the EPS control (D1= 0) can offer wider power transmission
range than the TPS control (D1 = 0) does, that will enhance
regulating flexibility. In addition, Fig. 13 shows that there are
many different combinations of (D1 , D2 ) in EPS control for the
same transmission power in TPS control. And the maximum
and minimum values of transmission power are obtained about
at D1+D2 = 0.5 and D1+D2 = 1, respectively, which agrees
well with the aforementioned theoretical analysis.
In order to verify the backflow power characterization of EPS
control, the transmission power and output voltage are both
in closed-loop control for 380W and 48V, respectively, the
transient waveforms of transmission power with input voltage
V1 = 220V is shown in Fig. 14(a), and the curves of backflow
power varied with input voltage V1 and inner phase-shift ratioD1
is shown in Fig. 14(b). It can be seen from Fig. 14, the backflow
power is bound up with input voltage V1 and inner phase-shift
ratio D1 , and it decreases with the increase of D1 and increases
with the increase of voltage conversion ratio k = V1 /(nV2 ).
Under different experimental conditions, the EPS control always
can generate less backflow power than the TPS control does, and
the minimum point of current stress is the minimum point of
14. ZHAO et al.: EXTENDED-PHASE-SHIFT CONTROL OF ISOLATED BIDIRECTIONAL DC–DC CONVERTER 4677
Fig. 14. (a) Transient waveforms of the transmission power when D1 is specified. (b) Curves of the backflow power varied with V1 when D1 is specified.
Fig. 15. Waveforms of vh1 , vh 2 , and iL in TPS and EPS control for the same transmission. (a) TPS control with V1 = 220V, V2 = 48V, and P = 380W. (b)
EPS control with V1 = 220V, V2 = 48V, P = 380W, and D1 = 0.2. (c) EPS control with V1 = 220V, V2 = 48V, P = 380W, and D1 = 0.4.
backflow power when V1 200 (i.e., k200/(2∗48)≈2), which
agrees well with the aforementioned theoretical analysis.
Fig. 15 shows the experimental waveforms of vh1, vh2 , and
iL in TPS and EPS control for the same transmission power, and
Fig. 16 shows the curves of current stress varied with V1 and
D1 . It can be seen that current stress is also bound up with input
voltage V1 and inner phase-shift ratio D1 , and it decreases with
the increase of D1 and increases with the increase of voltage
conversion ratio k = V1 /(nV2 ). Under different experimental
conditions, the EPS control always can generate less current
stress than the TPS control does.When the converter is operating
in the optimal point, the stress current achieves the minimum
value, which is consistent with the aforementioned theoretical
analysis.
Under the same experimental conditions with Figs. 14(b) and
16, Fig. 17 shows the efficiency curves of the converter in both
control methods. It can be easily found that the EPS control
can achieve higher efficiency than the TPS control, especially in
large voltage conversion ratio condition. And when the converter
Fig. 16. Curves of the current stress varied with V1 when D1 is specified.
15. 4678 IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 27, NO. 11, NOVEMBER 2012
Fig. 17. Curves of the efficiency curves varied with V1 when D1 is specified.
Fig. 18. Waveforms of IBDC in EPS control when k 1.
is operating in the optimal point, the efficiency achieves the
maximum value.
VI. DISCUSSION
All of the above analysis is based on the qualification that k ≥
1. In fact, when k 1 (nV2 V1 ), we just need to exchange the
operating modes of the left and the right H-bridges, as shown in
Fig. 18.
Similar to the analysis in Sections I and IV, we can derive that
the current stress of converter under EPS control is
max = V1
i
4fsL
1
k
(1 − D1) + (2D1 + 2D2 − 1)
. (48)
The transmission power is
P
= nV1V2
2fsL
D2(1 − D2) +
1
2D1(1 − D1 − 2D2 )
. (49)
The backflow power is
P
bf = nV1V2 [(1/k)(1 − D1) + (2D2 − 1)]2
16fsL(1/k) + 1) . (50)
In (48)–(50), the constraints are k 1, 0 ≤ D1 ≤ 1, 0 ≤ D2 ≤
1 and 0 ≤ D1+D2 ≤ 1. Similarly, the current stress of converter
under TPS control is
imax = V1
4fsL
(2D − 1 + (1/k). (51)
The transmission power is
P = nV1V2
2fsL
D(1 − D). (52)
The backflow power is
Pbf = nV1V2 [(1/k) + (2D − 1)]2
16fsL(1/k) + 1) . (53)
In (51)–(53), the constraints are k 1 and 0 ≤ D ≤ 1. Due to
1/k 1, comparing (48)–(53) with (9)–(12) and (14)–(16), we
can come to the conclusion that the performance at k 1 is
coincident with that at k 1.
The transmission power and output voltage are both in closed-loop
control for 1160W and 180V, respectively. Fig. 19 shows
the experimental waveforms of vh1, vh2 , and iL in TPS and EPS
control for the same transmission power, and Fig. 20 shows the
curves of current stress varied with V1 and D1 . Different with
Fig. 15, the input voltage in Fig. 19 is specified as 160V, i.e.,
k = 160/(2∗180) = 0.44. As can be seen from Figs. 19 and 20,
the current stress also decreases with the increasing of D1, but
decreases with the increasing of k = V1 /(nV2 ). In fact, when k
1 (nV2 V1 ), the current stress changes into an increasewith the
increasing of voltage conversion ratio 1/k = nV2 / V1 . Similarly,
the EPS control always can generate less current stress than the
TPS control does with the condition of k 1.
Fig. 21 shows the efficiency curves of the converter in both
control methods. It can be easily found that the EPS control
can achieve higher efficiency than the TPS control, especially in
large voltage conversion ratio condition. And when the converter
is operating in the optimal point, the efficiency achieves the
maximum value.
16. ZHAO et al.: EXTENDED-PHASE-SHIFT CONTROL OF ISOLATED BIDIRECTIONAL DC–DC CONVERTER 4679
Fig. 19. Waveforms of vh1 , vh 2 , and iL in TPS and EPS control for the same transmission. (a) TPS control with V1 = 160V, V2 = 180V, and P = 1160W.
(b) EPS control with V1 = 160V, V2 = 180V, P = 1160W, and D1 = 0.2. (c) EPS control with V1 = 160V, V2 = 180V, P = 1160W, and D1 = 0.4.
Fig. 20. Curves of the current stress varied with V1 (k 1) when D1 is
specified.
VII. CONCLUSION
IBDC is an everlasting key component to realize power distri-bution
between energy generation systems and storage systems
in microgrids. In order to overcome the inherent disadvantages
of TPS control of IBDC, a novel EPS control is proposed for
power distribution in microgrid in this paper. From the theo-retical
analysis and the experiments, it can be found that EPS
control has the following features: 1) EPS control expands reg-ulating
range of transmission power and enhances regulating
flexibility. 2) EPS control reduces power-circulating flow, and
thus reduces conduction losses and improves the system effi-ciency.
3) EPS control reduces current stress, and thus reduces
switching losses and prolongs the service life of devices. For
the same power level, the devices can be selected with lower
stress levels, which saves the cost. 4) EPS control is simple in
principle and easy to implement.
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Biao Zhao (S’11) received the B.S. degree from the
Department of Electrical Engineering, Dalian Uni-versity
of Technology, Dalian, China, in 2009. He
is currently working toward the Ph.D. degree in the
Department of Electrical Engineering, Tsinghua Uni-versity,
Beijing, China.
His current research interests include medium-voltage
power conversion system, bidirectional iso-lated
DC–DC converters, and uninterruptible power
supply system.
Qingguang Yu (M’01) received the B.S. and M.S.
degrees from Liaoning Engineering Technology Uni-versity,
Fuxin, China, in 1989 and 1991, respectively,
and the Ph.D. degree from China University of Min-ing
and Technology, Beijing, China, in 1994, all in
electrical engineering.
After 2 years of Post-Doctoral research work in
Electrical Engineering Department, he is currently
working as an Associate Professor with the Institute
of Flexible AC Transmission System (FACTS) of Ts-inghua
University in Beijing. His current research
interests include medium-voltage power conversion system, motor drive and
control, and power system automation FACTS in power plant and station.
Weixin Sun received the B.S. degree from Yan-shan
University, Qinghuangdao, China, in 2009, and
the M.S. degree from Tsinghua University, Beijing,
China, in 2011, all in electrical engineering.
He is currently working with China Power Engi-neering
Consulting Group Corporation, North China
Power Engineering Co. Ltd.