Universal demand for power increases due to continuous development to fulfil all these demand. Resources
are used with optimization. A high efficiency and high power factor converters are the major parts of energy
transfer system. This paper present a general review on single stage forward and flyback converter topologies to get
better its performance. This is paper presents a kind general idea of increasing efficiency and power factor of single
stage forward and fly back converter.
Design of Half Bridge LLC Resonant Converter for Low Voltage Dc ApplicationsIOSRJEEE
An advanced hybrid LLC series resonant converter with united flying-capacitor cell is proposed in this paper to permit the high step-down conversion in the high input voltage applications. The in-built flyingcapacitor branch in the primary side can efficiently share out the primary switch voltage stress related with the half-bridge LLC converters. And the input voltage can be shared correspondingly and automatically between the two series half-bridge components lacking additional balance circuit or control strategies owing to the built-in flying- capacitor cell. Likewise, the inherent soft switching performance in extensive load range that exists in the LLC converters is still kept to decrease the switching losses, which ensures the high efficiency. In addition, the proposed converter can be comprehensive to reduce the switch voltage stress byemploying stacked connection. Finally, a 500∼640 Vinput 48 Voutput 1 kW prototype is built and tested to verify the efficiency of the proposed converter. The results prove that the proposed converter is an excellent candidate for the high input voltage and high step-down dc/dc conversion systems.
New Topology for Transformer less Single Stage -Single Switch AC/DC ConverterIJMER
This paper presents a transformer less single-stage single-switch ac/dc converter suitable for universal line applications (90–270 Vrms). The topology consists of a buck-type power-factor correction (PFC) cell with a buck–boost dc/dc cell and part of the input power is directly coupled to the output after the first power processing. With this direct power transfer and sharing capacitor voltages, the converter is able to achieve efficient power conversion, high power factor, low voltage stress on intermediate bus (less than 120 V) and low output voltage without a high step-down transformer. The absence of transformer reduces the size of the circuit , component counts and cost of the converter. Unlike most of the boost-type PFC cell, the main switch of the proposed converter only handles the peak inductor current of dc/dc cell rather than the superposition of both inductor currents. Tight voltage regulation is provided by using PID controller. Detailed analysis and design procedures and simulation of the proposed circuit are given .
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.
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.
Performance and Analysis of Hybrid Multilevel Inverter fed Induction Motor Drivernvsubbarao koppineni
This paper presents the Five level inverter with single DC source which is used to generate a five level output with two bridges and six switches and performance of three phase induction motor is analyzed when connected to PV array For this two identical dc sources of 50V each for two bridges in five levels using Multi level inverter and five level output is obtained by using a single DC source of 100V with six switches. A virtual DC source (charged capacitor acts as virtual DC source) is used for getting the output. The same technique is implemented for three-phase circuit i.e. by using single DC source. An asynchronous motor (three-phase) is connected as load and its performance characteristics are analyzed. And further the DC source is replaced by a renewable resource such as solar panels, fuel cell etc. and DC voltage is obtained. Performance characteristics of three-phase asynchronous motor are analyzed with PV array connected. The method can be easily extended to an m-level inverter.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Design of Half Bridge LLC Resonant Converter for Low Voltage Dc ApplicationsIOSRJEEE
An advanced hybrid LLC series resonant converter with united flying-capacitor cell is proposed in this paper to permit the high step-down conversion in the high input voltage applications. The in-built flyingcapacitor branch in the primary side can efficiently share out the primary switch voltage stress related with the half-bridge LLC converters. And the input voltage can be shared correspondingly and automatically between the two series half-bridge components lacking additional balance circuit or control strategies owing to the built-in flying- capacitor cell. Likewise, the inherent soft switching performance in extensive load range that exists in the LLC converters is still kept to decrease the switching losses, which ensures the high efficiency. In addition, the proposed converter can be comprehensive to reduce the switch voltage stress byemploying stacked connection. Finally, a 500∼640 Vinput 48 Voutput 1 kW prototype is built and tested to verify the efficiency of the proposed converter. The results prove that the proposed converter is an excellent candidate for the high input voltage and high step-down dc/dc conversion systems.
New Topology for Transformer less Single Stage -Single Switch AC/DC ConverterIJMER
This paper presents a transformer less single-stage single-switch ac/dc converter suitable for universal line applications (90–270 Vrms). The topology consists of a buck-type power-factor correction (PFC) cell with a buck–boost dc/dc cell and part of the input power is directly coupled to the output after the first power processing. With this direct power transfer and sharing capacitor voltages, the converter is able to achieve efficient power conversion, high power factor, low voltage stress on intermediate bus (less than 120 V) and low output voltage without a high step-down transformer. The absence of transformer reduces the size of the circuit , component counts and cost of the converter. Unlike most of the boost-type PFC cell, the main switch of the proposed converter only handles the peak inductor current of dc/dc cell rather than the superposition of both inductor currents. Tight voltage regulation is provided by using PID controller. Detailed analysis and design procedures and simulation of the proposed circuit are given .
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.
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.
Performance and Analysis of Hybrid Multilevel Inverter fed Induction Motor Drivernvsubbarao koppineni
This paper presents the Five level inverter with single DC source which is used to generate a five level output with two bridges and six switches and performance of three phase induction motor is analyzed when connected to PV array For this two identical dc sources of 50V each for two bridges in five levels using Multi level inverter and five level output is obtained by using a single DC source of 100V with six switches. A virtual DC source (charged capacitor acts as virtual DC source) is used for getting the output. The same technique is implemented for three-phase circuit i.e. by using single DC source. An asynchronous motor (three-phase) is connected as load and its performance characteristics are analyzed. And further the DC source is replaced by a renewable resource such as solar panels, fuel cell etc. and DC voltage is obtained. Performance characteristics of three-phase asynchronous motor are analyzed with PV array connected. The method can be easily extended to an m-level inverter.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Single-Phase Inverter with Energy Buffer and DC-DC Conversion CircuitsAsoka Technologies
This paper proposes a new single-phase inverter topology and describes the control method for the proposed inverter. The inverter consists of an energy buffer circuit, a dc-dc conversion circuit and an H-bridge circuit. The energy buffer circuit and H-bridge circuit enable the proposed inverter to output a multilevel voltage according to the proposed pulse width modulation (PWM) technique. The dc-dc conversion circuit can charge the buffer capacitor continuously because the dc-dc conversion control cooperates with the PWM. Simulation results confirm that the proposed inverter can reduce the voltage harmonics in the output and the dc-dc conversion current in comparison to a conventional inverter consisting of a dc-dc conversion circuit and H-bridge circuit. Experiments demonstrate that the proposed inverter can output currents of low total harmonic distortion and have higher efficiency than the conventional inverter. In addition, it is confirmed that these features of the proposed inverter contribute to the suppression of the circuit volume in spite of the increase in the number of devices in the circuit.
This paper proposes a non-isolated soft-switching bidirectional dc/dc converter for interfacing energy storage in DC microgrid. The proposed converter employs a half-bridge boost converter at input port followed by a LCC resonant tank to assist in soft-switching of switches and diodes, and finally a voltage doubler circuit at the output port to enhance the voltage gain by two times. The LCC resonant circuit also adds a suitable voltage gain to the converter. Therefore, overall high voltage gain of the converter is obtained without a transformer or large number of multiplier circuit. For operation in buck mode, the high side voltage is divided by half with capacitive divider to gain higher step-down ratio. The converter is operated at high frequency to obtain low output voltage ripple, reduced magnetics and filters. Zero voltage turn-on is achieved for all switches and zero current turn-on and turn-off is achieved for all diodes in both modes i.e., buck/boost operation. Voltage stress across switches and diode is clamped naturally without external snubber circuit. An experimental prototype has been designed, built and tested in the laboratory to verify the performance of the proposed converter.
Time Response enhancement utilizing photovoltaic based cascaded Landsman Converter (LC) structure is one of the soft strategies in the recent scenario. The prime function of a DC-DC Landsman converter is to optimize the output power of the photovoltaic array and reduce the output voltage ripples. This paper reveals the demonstration and simulation of the Cascaded Landsman Converter Inverter System (CLCIS) with a PV source. MATLAB Simulink-model for CLCIS has been created utilizing the components of Simulink and closed-loop examinations are performed with PI and Fractional-Order-PID (FOPID) Controllers. The present work deal with the comparison of transient and steady-state time responses of CLCIS with PI and FOPID controllers. The outcomes demonstrate that dynamic reaction is enhanced by utilizing FOPID controller.
Voltage Control of Dual Active Bridge Converter for CO-Amorphous Core Materia...kuldeep12555
Solid-State Transformer (SST) provides versatile power system operation. In the smart world, there are technologies where everything is incorporated that reduce the size and eventually save time in delivering a fast process. It has been seen that solid-state transformer voltage begins to decrease during operation that needs to be regulated through some control strategy. In this paper, a Dual Active Bridge (DAB) converter has been used to control the voltage of SST that employs the Single-Phase Shift (SPS) technique. For further efficiency improvement Co73(Si, B)27 co-amorphous material has been used for the core of SST because co-amorphous alloy has much lower loss compared with Fe-amorphous cores and have limited saturation flux density. Real-time parameters of core have been used in the analysis. It has been evident from the results that DAB dc-dc converter-based SST with SPS control technique is simple and offers better performance compared to stand-alone SST. It improves the overall performance and efficiency of the system. This paper has been accomplished in Matlab® / Simulink environment.
Keywords: Co73 (Si, B)27 Amorphous Core Material; Solid-State transformer (SST); Dual Active Bridge (DAB); High
voltage (HV) Application.
An Asymmetrical Dc-Dc Converter with a High Voltage GainIJMER
An asymmetrical full bridge converter is proposed in the paper. The proposed converter
achieves zero voltage switching of all the power switches. Zero current switching of all the output diodes
are also achieved here. This in turn provides a highly efficienct operation. The proposed converter can
provide a high voltage gain and the voltages across the semi- conductor devices are effectively clamped.
The converter can be utilised effectively in high voltage applications as embedded systems, renewable
energy systems, fuel cells, mobility applications and uninterrupted power supply
Transformerless Buck-Boost Converter With Positive Output Voltage and Nominal...paperpublications3
Abstract: This article deals with a transformerless buck-boost converter with simple structure. By inserting an additional switched network into the traditional buck-boost converter new converter is obtained. Compared with the traditional buck-boost converter, its voltage gain is quadratic of the traditional buck-boost converter. It can operate in a wide range of output voltage, that is, the proposed buck-boost converter can achieve high or low voltage gain without extreme duty cycle. Moreover, the output voltage of this transformerless buck-boost converter is common-ground with the input voltage, and its polarity is positive. The two power switches of the proposed buck-boost converter operate synchronously. The operating principles and the steady-state analyses for the buck-boost converter operating in CCM are presented. The PSIM simulations are provided to compare and validate the effectiveness of the buck-boost converter.
Keywords: Buck-Boost, Transformerless, Positive Output Voltage, Quadratic Gain.
Title: Transformerless Buck-Boost Converter With Positive Output Voltage and Nominal Duty Ratio
Author: Aleena Paul K, Prof.Sini Paul, Prof.Geethu James
International Journal of Recent Research in Electrical and Electronics Engineering (IJRREEE)
Paper Publications
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
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.
Analysis of Fuel Cell Based Multilevel DC-DC Boost Converter for Induction MotorIJMTST Journal
In this paper new topologies and interleaving modulation concepts for multilevel DC-DC boost converter
enabling a significantly less loss and a reduced chip size of the power semiconductors are proposed. The
distributed generation (DG) systems based on the renewable energy sources have rapidly developed in
recent years. These DG systems are powered by micro sources such as fuel cells, photovoltaic (PV) systems,
and batteries. Fuel cells are considered to be one of the most promising sources of distributed energy because
of their high efficiency, low environmental impact and scalability. Non-isolated high step-up DC-DC
converters are required in the industrial applications. Many of these conventional DC–DC converters have the
disadvantages of operating at high duty-cycle, high switch voltage stress and high diode peak current. A
three-level step up converter is implemented to boost the fuel cell stack voltage of 96V to 340V. The proposed
converter consists a system of fuel cell based Multilevel DC-DC converter with PI controller is modeled and
simulated by using Matlab/Simulink.
Multilevel DC Link Inverter with Reduced Switches and BatteriesIJPEDS-IAES
Multilevel inverters are the best solution for medium and high voltage power electronic drives. Because of its unique characteristic of synthesizing sinusoidal voltage with less harmonic contents using several DC sources. In a three phase multilevel inverter, each phase of a cascaded H-bridge inverter requires ‘n’ DC sources to obtain 2n + 1 output voltage levels. One particular disadvantage is that, it increases number of power semiconductor switches. To overcome this disadvantage a multilevel DC link inverter (MLDCLI) with reduced number of switches and batteries is proposed.
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.
A novel single phase cascaded h-bridge inverter with new cell configuration a...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
The intention of this paper is to identify a suitable controller for closed loop multi converter system for multiple input sources and to improve time response of high-gain-step up-converter. Closed-loop Multi Converter System (MCS) is utilized to regulate load-voltage. This effort recommends suitable-controller for closed-two loop-controlled-SEPIC-REBOOST Converter fed DC motor. The estimation of the yield in open-two loop and closed- two-loop-circuit has been done using MATLAB or Simulink. Closed-two loop-control of Multi Converter System with Propotional+Integral (PI)- Propotional+Integral (PI) and Proportional+Resonant (PR) - Proportional+Resonant (PR) Controllers are investigated and their responses are evaluated in conditions of rise time, peak time, settling time and steady state error. It is seen that current-mode PR-PR controlled MCS gives better time domain response in terms of motor speed. A Prototype of MCS has been fabricated in the laboratory and the experimental-results are authenticated with the simulation-results.
The construction industry involves risky and unhealthy operations which result in many human tragedies, to lose
enthusiasm of workers, disrupt construction, delay progress, and adversely affect cost, productivity, and reputation. The
complex nature of construction and hazards it have occupational health and safety in construction work should design table and
continue throughout the construction phases until the safety and health of every end users is ensured. Safety is a major concern
for construction companies, as it is a source of substantial direct and indirect costs. In some countries, the rate of total workplace
injuries from construction activities can be as high as at least 50%. This is undoubtedly a serious matter warranting urgent
attention. This paper reviewed that the safety problems at construction site with fetal injuries caused by it with help of different
graphical data of agencies .It gives detailed information regarding about the injuries type and physical loss of human from this.
This study also revealed that the importance of safety in construction should pay more attention as the injuries loss the human
life and also delay in completion of project
dents. Typically there is need for access to computational power, network connectivity and specialized
software.The classical solution for this problem is to delegate physical hardware for all of these needs. This is
unpractical and results in an inefficient use of hardware, electricity and administrative resources.
A self-service virtualization system could benefit these institutions by making computing resources more easily
available to its students and researchers, and by improving the utilization of hardware resources. In this project we
identify the requirements for such a system, by installing and con- figuring a prototype private cloud solution for
students at the college.
Single-Phase Inverter with Energy Buffer and DC-DC Conversion CircuitsAsoka Technologies
This paper proposes a new single-phase inverter topology and describes the control method for the proposed inverter. The inverter consists of an energy buffer circuit, a dc-dc conversion circuit and an H-bridge circuit. The energy buffer circuit and H-bridge circuit enable the proposed inverter to output a multilevel voltage according to the proposed pulse width modulation (PWM) technique. The dc-dc conversion circuit can charge the buffer capacitor continuously because the dc-dc conversion control cooperates with the PWM. Simulation results confirm that the proposed inverter can reduce the voltage harmonics in the output and the dc-dc conversion current in comparison to a conventional inverter consisting of a dc-dc conversion circuit and H-bridge circuit. Experiments demonstrate that the proposed inverter can output currents of low total harmonic distortion and have higher efficiency than the conventional inverter. In addition, it is confirmed that these features of the proposed inverter contribute to the suppression of the circuit volume in spite of the increase in the number of devices in the circuit.
This paper proposes a non-isolated soft-switching bidirectional dc/dc converter for interfacing energy storage in DC microgrid. The proposed converter employs a half-bridge boost converter at input port followed by a LCC resonant tank to assist in soft-switching of switches and diodes, and finally a voltage doubler circuit at the output port to enhance the voltage gain by two times. The LCC resonant circuit also adds a suitable voltage gain to the converter. Therefore, overall high voltage gain of the converter is obtained without a transformer or large number of multiplier circuit. For operation in buck mode, the high side voltage is divided by half with capacitive divider to gain higher step-down ratio. The converter is operated at high frequency to obtain low output voltage ripple, reduced magnetics and filters. Zero voltage turn-on is achieved for all switches and zero current turn-on and turn-off is achieved for all diodes in both modes i.e., buck/boost operation. Voltage stress across switches and diode is clamped naturally without external snubber circuit. An experimental prototype has been designed, built and tested in the laboratory to verify the performance of the proposed converter.
Time Response enhancement utilizing photovoltaic based cascaded Landsman Converter (LC) structure is one of the soft strategies in the recent scenario. The prime function of a DC-DC Landsman converter is to optimize the output power of the photovoltaic array and reduce the output voltage ripples. This paper reveals the demonstration and simulation of the Cascaded Landsman Converter Inverter System (CLCIS) with a PV source. MATLAB Simulink-model for CLCIS has been created utilizing the components of Simulink and closed-loop examinations are performed with PI and Fractional-Order-PID (FOPID) Controllers. The present work deal with the comparison of transient and steady-state time responses of CLCIS with PI and FOPID controllers. The outcomes demonstrate that dynamic reaction is enhanced by utilizing FOPID controller.
Voltage Control of Dual Active Bridge Converter for CO-Amorphous Core Materia...kuldeep12555
Solid-State Transformer (SST) provides versatile power system operation. In the smart world, there are technologies where everything is incorporated that reduce the size and eventually save time in delivering a fast process. It has been seen that solid-state transformer voltage begins to decrease during operation that needs to be regulated through some control strategy. In this paper, a Dual Active Bridge (DAB) converter has been used to control the voltage of SST that employs the Single-Phase Shift (SPS) technique. For further efficiency improvement Co73(Si, B)27 co-amorphous material has been used for the core of SST because co-amorphous alloy has much lower loss compared with Fe-amorphous cores and have limited saturation flux density. Real-time parameters of core have been used in the analysis. It has been evident from the results that DAB dc-dc converter-based SST with SPS control technique is simple and offers better performance compared to stand-alone SST. It improves the overall performance and efficiency of the system. This paper has been accomplished in Matlab® / Simulink environment.
Keywords: Co73 (Si, B)27 Amorphous Core Material; Solid-State transformer (SST); Dual Active Bridge (DAB); High
voltage (HV) Application.
An Asymmetrical Dc-Dc Converter with a High Voltage GainIJMER
An asymmetrical full bridge converter is proposed in the paper. The proposed converter
achieves zero voltage switching of all the power switches. Zero current switching of all the output diodes
are also achieved here. This in turn provides a highly efficienct operation. The proposed converter can
provide a high voltage gain and the voltages across the semi- conductor devices are effectively clamped.
The converter can be utilised effectively in high voltage applications as embedded systems, renewable
energy systems, fuel cells, mobility applications and uninterrupted power supply
Transformerless Buck-Boost Converter With Positive Output Voltage and Nominal...paperpublications3
Abstract: This article deals with a transformerless buck-boost converter with simple structure. By inserting an additional switched network into the traditional buck-boost converter new converter is obtained. Compared with the traditional buck-boost converter, its voltage gain is quadratic of the traditional buck-boost converter. It can operate in a wide range of output voltage, that is, the proposed buck-boost converter can achieve high or low voltage gain without extreme duty cycle. Moreover, the output voltage of this transformerless buck-boost converter is common-ground with the input voltage, and its polarity is positive. The two power switches of the proposed buck-boost converter operate synchronously. The operating principles and the steady-state analyses for the buck-boost converter operating in CCM are presented. The PSIM simulations are provided to compare and validate the effectiveness of the buck-boost converter.
Keywords: Buck-Boost, Transformerless, Positive Output Voltage, Quadratic Gain.
Title: Transformerless Buck-Boost Converter With Positive Output Voltage and Nominal Duty Ratio
Author: Aleena Paul K, Prof.Sini Paul, Prof.Geethu James
International Journal of Recent Research in Electrical and Electronics Engineering (IJRREEE)
Paper Publications
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
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.
Analysis of Fuel Cell Based Multilevel DC-DC Boost Converter for Induction MotorIJMTST Journal
In this paper new topologies and interleaving modulation concepts for multilevel DC-DC boost converter
enabling a significantly less loss and a reduced chip size of the power semiconductors are proposed. The
distributed generation (DG) systems based on the renewable energy sources have rapidly developed in
recent years. These DG systems are powered by micro sources such as fuel cells, photovoltaic (PV) systems,
and batteries. Fuel cells are considered to be one of the most promising sources of distributed energy because
of their high efficiency, low environmental impact and scalability. Non-isolated high step-up DC-DC
converters are required in the industrial applications. Many of these conventional DC–DC converters have the
disadvantages of operating at high duty-cycle, high switch voltage stress and high diode peak current. A
three-level step up converter is implemented to boost the fuel cell stack voltage of 96V to 340V. The proposed
converter consists a system of fuel cell based Multilevel DC-DC converter with PI controller is modeled and
simulated by using Matlab/Simulink.
Multilevel DC Link Inverter with Reduced Switches and BatteriesIJPEDS-IAES
Multilevel inverters are the best solution for medium and high voltage power electronic drives. Because of its unique characteristic of synthesizing sinusoidal voltage with less harmonic contents using several DC sources. In a three phase multilevel inverter, each phase of a cascaded H-bridge inverter requires ‘n’ DC sources to obtain 2n + 1 output voltage levels. One particular disadvantage is that, it increases number of power semiconductor switches. To overcome this disadvantage a multilevel DC link inverter (MLDCLI) with reduced number of switches and batteries is proposed.
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.
A novel single phase cascaded h-bridge inverter with new cell configuration a...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
The intention of this paper is to identify a suitable controller for closed loop multi converter system for multiple input sources and to improve time response of high-gain-step up-converter. Closed-loop Multi Converter System (MCS) is utilized to regulate load-voltage. This effort recommends suitable-controller for closed-two loop-controlled-SEPIC-REBOOST Converter fed DC motor. The estimation of the yield in open-two loop and closed- two-loop-circuit has been done using MATLAB or Simulink. Closed-two loop-control of Multi Converter System with Propotional+Integral (PI)- Propotional+Integral (PI) and Proportional+Resonant (PR) - Proportional+Resonant (PR) Controllers are investigated and their responses are evaluated in conditions of rise time, peak time, settling time and steady state error. It is seen that current-mode PR-PR controlled MCS gives better time domain response in terms of motor speed. A Prototype of MCS has been fabricated in the laboratory and the experimental-results are authenticated with the simulation-results.
The construction industry involves risky and unhealthy operations which result in many human tragedies, to lose
enthusiasm of workers, disrupt construction, delay progress, and adversely affect cost, productivity, and reputation. The
complex nature of construction and hazards it have occupational health and safety in construction work should design table and
continue throughout the construction phases until the safety and health of every end users is ensured. Safety is a major concern
for construction companies, as it is a source of substantial direct and indirect costs. In some countries, the rate of total workplace
injuries from construction activities can be as high as at least 50%. This is undoubtedly a serious matter warranting urgent
attention. This paper reviewed that the safety problems at construction site with fetal injuries caused by it with help of different
graphical data of agencies .It gives detailed information regarding about the injuries type and physical loss of human from this.
This study also revealed that the importance of safety in construction should pay more attention as the injuries loss the human
life and also delay in completion of project
dents. Typically there is need for access to computational power, network connectivity and specialized
software.The classical solution for this problem is to delegate physical hardware for all of these needs. This is
unpractical and results in an inefficient use of hardware, electricity and administrative resources.
A self-service virtualization system could benefit these institutions by making computing resources more easily
available to its students and researchers, and by improving the utilization of hardware resources. In this project we
identify the requirements for such a system, by installing and con- figuring a prototype private cloud solution for
students at the college.
Molecular dynamics simulation is in-comparably superior to both experiments method and
theoretical analysis. However, because computational effort of molecular dynamics simulation is very
large, especially, the simulation of a large number of Carbon Nano Tube (CNT) particles, general CPU
serial algorithm implementation is inefficient and slow. A Compute Unified Device Architecture (CUDA)
based parallel algorithm of CNT molecular dynamics is proposed in this paper to take advantage of the
data parallelism of Graphic Processing Unit (GPU). A CNT is divided to several blocks and processed
parallel in the GPU. Experimental results show that the algorithm can obtain a speed-up more than 10
times to the CPU serial algorithm in a low-configured graphics card that has only 16 GPU stream
processors.
The modern trend is to develop IC
Engine of increased power capacity. One of
the design criteria is the endeavor to reduce
the structures weight and thus to reduce fuel
consumption. This has been made possible
by improved engine design. In the internal
combustion engine there are many
reciprocating parts which are responsible for
giving the motion to the engine. The piston
is “Heart” of the engine and its working
condition is the worst one of the key parts of
engine in the working environment. So it is
very important for design and structural
analysis of the piston.
Abstract: The processing power of computing devices has increased with number of available cores. This paper presents an approach
towards clustering of categorical data on multi-core platform. K-modes algorithm is used for clustering of categorical data which
uses simple dissimilarity measure for distance computation. The multi-core approach aims to achieve speedup in processing. Open
Multi Processing (OpenMP) is used to achieve parallelism in k-modes algorithm. OpenMP is a shared memory API that uses
thread approach using the fork-join model. The dataset used for experiment is Congressional Voting Dataset collected from UCI
repository. The dataset contains votes of members in categorical format provided in CSV format. The experiment is performed for
increased number of clusters and increasing size of dataset.
This paper deals with the overview of latest video coding standard High-Efficiency Video
Coding (HEVC). Also this work presents a performance comparison of the two latest video coding
standards H.264/MPEG-AVC and H.265/MPEG-HEVC. According to the experimental results, which
were obtained for a whole test set of video sequences by using similar encoding configurations,
H.265/MPEG-HEVC provides significant average bit-rate savings of around 40%.
Keywords: - CABAC, CAVLC, H.264/AVC, HEVC PSNR and SBAC.
A Silencer is a part of the exhaust system of an automobile that plays a vital role. It needs to
have modes that are located away from the frequencies that the engine operates at, whether the engine be
idling or running at the maximum amount of revolutions per second. The purpose of the design project
performed was to determine which modes are very high and may affect the automobile adversely while in
operation. Research was performed prior to the test to determine which frequencies to look for modes at.
It was determined to conduct the experiment so data from 20 Hz to 20 KHz could be collected. The force
was generated by running the engine at different speed. Acceleration is measured by using FFT analyzer
by selecting the points on the Silencer were chosen, after looking at the data and determined to be under
damped. Therefore, our design study suggests increasing the mass, increase the damping, or providing a
negative stiffness to make the silencer more damped.
The purpose of this report is also to the study the harmful effects of noise caused by it on Engine.
In India, the transportation sector is growing rapidly and number of vehicles on Indian roads is increasing
at very fast rate. This has lead to overcrowded roads and noise pollution. Engine vibration is one of the
major source of noise in vehicles. So, it is necessary to study noise generated by four stroke petrol engine.
The study of noise generated by four stroke petrol engine is carried out with or without mufflers to check
the effectiveness of the muffler
Robotics is the branch of technology that deals with the design, construction, operation
and application of robots and computer systems for their control, sensory feedback, and information
processing. These technologies deal with automated machines that can take the place of humans, in
hazardous or manufacturing processes, or simply just resemble humans. Many of today's robots are
inspired by nature contributing to the field of bio-inspired robotics
effects on kefir properties and antioxidant activity during 4 weeks cold (4 °C) storage. Carob
flours differed in composition, mucilage yield, antioxidant activity and phenolic components analyzed by
HPLC. Bacterial count increased during the first week of kefir storage with carob supplementation
stimulating bacterial growth similar to inulin. Bacterial viability and titratable acidity of carob
supplemented kefir increased, whereas pH decreased during storage. The antioxidant activity of kefirs
generally increased during storage attaining maximum level at 14 days with the supplemented kefirs
exhibiting higher activity compared to the control plain kefir.
RK7(5) is a numerical method was used to minimize the local truncation error using selection step size algorithm.
Time multiplexing CNN simulator was modied using RK7(5) to improve the performance of the simulator and the
quality of the output image for edge detection. The results showed better performance than those in the literature.
This paper is focused towards extraction of important words from conversations, and then these
words are utilized to recover a small number of relevant documents, which can be given to users as per
their needs. In any case, even a short audio fragment contains of large number of words, which are
conceivably identified with a few topics and also, using automatic speech recognition (ASR) framework
reduces errors in the output. It is difficult to provide the data needs of the conversation members
appropriately. A calculation to remove decisive words from the yield of an ASR framework (or a manual
transcript for testing) to support the potentially differing qualities of subjects and decrease ASR
commotion is proposed. At that point, a technique is used to make many implicit queries from the selected
keywords. These queries will in return produce list of relevant documents. The scores demonstrate that our
proposition is modified over past systems that consider just word re-occurrence or topic closeness, and
speaks to an appropriate answer for a report recommender framework to be utilized as a part of
discussions.
Medical informatics growth can be observed now days. Advancement in different medical fields
discovers the various critical diseases and provides the guidelines for their cure. This has been possible
only because of well heeled medical databases as well as automation of data analysis process. Towards
this analysis process lots of learning and intelligence is required, the data mining techniques provides the
basis for that and various data mining techniques are available like Decision tree Induction, Rule Based
Classification or mining, Support vector machine, Stochastic classification, Logistic regression, Naïve
bayes, Artificial Neural Network & Fuzzy Logic, Genetic Algorithms. This paper provides the basic of
data mining with their effective techniques availability in medical sciences & reveals the efforts done on
medical databases using data mining techniques for human disease diagnosis.
With the technology today, detection of pedestrian was introduced to decrease the accidents in the roads. It was implemented on the traffic lights and cars. In this paper, integration of face detection and pedestrian takes place on the device called Raspberry Pi. OpenCV was used for the detections and programmed in Python. The webcam was used to capture images in real-time. The image was processed at the microprocessor. When pedestrians were detected, the microprocessor played the recorded voice and outputs it to the connecting speaker to notify those pedestrians or the pedestrian to wait before crossing until such time. The microprocessor sends a signal to the Gizduino to process the time of the red lights on state. The microcontroller was programmed with the traffic signals. When it receives a signal from the microprocessor, it added an extra seconds to the red lights on state. Afterwards when it returned, it changed back to its original on state. The success rate was 80% this shows the two detection was integrated in the system successfully worked.
The main goal of this paper to produce new low power solutions for very large scale
integration(VLSI).The main focus of this research on the power consumption, which is showing an
ever-increasing growth with scaling down of the technologies. The full adder is the most important
component of any digital system applications. To limit the power dissipation, this full adder is
designed with adiabatic technique PFAL and it compare with partial adiabatic technique ECRL.
These analysis have done on TANNER simulator V 7 technology. The power is reduced up to 70-
80% as compared to other methods.
A digital watermarking scheme based on integer wavelet transform and histogram techniques is
proposed in this paper. Lifting scheme based integer wavelet transform is used to provide ease of
transformation of compressed data and to increase the data embedding capacity. Also histogram technique
which is one of the reversible data hiding is used to embed the secret data into original image and retrieve the
original data back after extraction. The AES encryption is used to encrypt the embedded image to provide
authentication. This algorithm is developed using verilog code and implemented on FPGA Artix 7 board in
order to increase throughput, reduce area and power consumption.
In this modern age of competition, manufacturing sector is no exemption. With increasing
customer demands the precision and accuracy required in the manufacturing of component is very high. In
order to have mass production and high productivity of any component the availability of an SPM
(Special Purpose Machine) is a must. The hose-clamp finds various applications in moderate pressure
devices like the automotive pipes, LPG pipes etc. This paper deals with bringing in simple but effective
machine to roll the hose clamp into its circular form and to enhance the quality and quantity of
production.
Keywords — SPM, Hose-Clamp, Productivity.
As many of the industries use induction motors. So, controlling of induction motor plays a very vital role. So,
our project concentrates on controlling the speed of induction motor using Android phone remotely by the help of the
Bluetooth technology. We use Android application which uses Bluetooth to connect to the Bluetooth modem of
control circuit which is connected to the motor. Bluetooth modem is interfaced with microcontroller. The Bluetooth
slave modem receives the command from the mobile phone. The Bluetooth modem sends the signal to the
Microcontroller. The Microcontroller decodes the signal and sends to the relays. Then, respective relay operates to
change the speed of Induction motor from 0% to 100%.
We are not only controlling the speed of the Induction motor, using feedback network we can also detect the
over temperature, high voltage, low voltage, MCB tripping on account of any faults. And we are also adding an extra
application which is very important in industries. That is, monitoring of phase lines. Because these types of
uncertainties like over temperature, high voltage, low voltage etc are likely to happen in Industries. So, this project
will be very helpful in industries, house hold, shopping malls etc.
The paper investigates the development of the stone vessels industry in Ancient Egypt during the periods from the
Middle Kingdom to Third Intermediate Period. The paper presents samples of the stone vessels during those periods and tries to
analyze each sample showing its characteristics and location if known. The design of each stone vessel is outlined and the
decoration (if any) is investigated. The development aspects of the stone vessels industry is investigated highlighting the
innovations of the designs and their manufacturing. The maximum development of stone vessels in the 18th dynasty is outlined
with example models from the rein of Pharaoh Tutankhamun.
This project is proposed to integrate the Fuel cell emulator with a boost converter and load the DC motor
and the performance analysis is done. Fuel cell as a renewable energy source is considered to be one of the most
promising sources of electrical power. The characteristics of fuel cell is such that the DC power extracted from it is
at low voltage level, this project proposes a prototype of a new power electronics based fuel cell emulator. After
proposing a fuel cell emulator, it is integrated with a boost converter and DC motor is loaded. After the successful
working of the boost converter, it can be directly connected with the actual Fuel Cell Systems (FCS) to satisfy the
DC motor load which is integrated with fuel cell emulator and boost converter.
GET IEEE BIG DATA,JAVA ,DOTNET,ANDROID ,NS2,MATLAB,EMBEDED AT LOW COST WITH BEST QUALITY PLEASE CONTACT BELOW NUMBER
FOR MORE INFORMATION PLEASE FIND THE BELOW DETAILS:
Nexgen Technology
No :66,4th cross,Venkata nagar,
Near SBI ATM,
Puducherry.
Email Id: praveen@nexgenproject.com
Mobile: 9791938249
Telephone: 0413-2211159
www.nexgenproject.com
GET IEEE BIG DATA,JAVA ,DOTNET,ANDROID ,NS2,MATLAB,EMBEDED AT LOW COST WITH BEST QUALITY PLEASE CONTACT BELOW NUMBER
FOR MORE INFORMATION PLEASE FIND THE BELOW DETAILS:
Nexgen Technology
No :66,4th cross,Venkata nagar,
Near SBI ATM,
Puducherry.
Email Id: praveen@nexgenproject.com
Mobile: 9791938249
Telephone: 0413-2211159
www.nexgenproject.com
Design of an Integrated Power Factor Converter with PI Controller for Low Pow...IOSRJEEE
In this paper, an integrated power factor converter with PI controller is proposed. The circuit topology is obtained by integrating two converters namely the buck converter and a boost converter. The boost converter is normally a step up converter which obtain an unity power factor and performs low harmonics at the input. Based on the simple circuit topology and easy control the boost converter or buck-boost converter is used as power factor correctors. Similarly the buck converter regulates the dc-link voltage and provide a stable dc output voltage. To achieve unity power factor, the output voltage of both converter should be higher than the amplitude of the ac line voltage. The steady -state analysis is developed and a design is provided
A Five – Level Integrated AC – DC ConverterIJTET Journal
This paper presents the implementation of a new five – level integrated AC – DC converter with high input power factor and reduced input current harmonics complied with IEC1000-3-2 harmonic standards for electrical equipments. The proposed topology is a combination of boost input power factor pre – regulator and five – level DC – DC converter. The single – stage PFC (SSPFC) approach used in this topology is an alternative solution to low – power and cost – effective applications.
International Refereed Journal of Engineering and Science (IRJES)irjes
The core of the vision IRJES is to disseminate new knowledge and technology for the benefit of all, ranging from academic research and professional communities to industry professionals in a range of topics in computer science and engineering. It also provides a place for high-caliber researchers, practitioners and PhD students to present ongoing research and development in these areas.
Design and implementation of Closed Loop Control of Three Phase Interleaved P...IJMTST Journal
A single-phase, three-level, single-stage power-factor corrected AC/DC converter operated under closed
loop manner is presented. That operates with a single controller to regulate the output voltage and the input
inductor act as a boost inductor to have a single stage power factor correction with good output response. The
paper deals with a new single stage three level ac-dc converter which performs both power factor correction
and voltage regulation in a single stage. The proposed converter has two separate controllers, one for power
factor correction and the other for regulating the output voltage. A comprehensive review of the existing single
stage topologies has been carried out. Then the operating principle, control scheme and the design of the new
converter are presented. The proposed converter is having an input power factor close to unity and better
voltage regulation compared to the conventional ac-dc converter topologies. Proposed topology is evaluated
through Matlab/Simulink platform and simulation results are conferred.
A Novel Integrated AC-DC Five Level Converter Strategy for Power Factor Corre...IJMTST Journal
Multilevel configuration has the advantage of its simplicity and modularity over the configurations of the other converters. With the application of multilevel converter in the high voltage and large power occasions in recent years, its modulation strategy has become a research hot point in the field of power electronics. The proposed power-factor-correction circuit can achieve unity power factor and ripple-free input current using a coupled inductor. The proposed rectifier can also produce input currents that do not have dead band regions and an output current that is continuous for all load conditions. The features of this converter are that it has lower input section peak current stresses and a better harmonic content than similar converter with a non-interleaved output, the output current is continuous for all load ranges, and the dc bus voltage is less than 450 for all line and load conditions. In this paper, the operation of the new converter is explained, its steady-state characteristics are determined by analysis, and these characteristics are used to develop a procedure for the design of the converter. Hence the simulation results are obtained using MATLAB/SIMULINK software. The proposed system provides a closed loop control for variable output voltage. The SSPFC AC/DC converter can operate with lower peak voltage stresses across the switches and the DC bus capacitors as it is a three-level converter. The proposed concept can be implemented with 5-level for efficient output voltage.
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.
PV Cell Fed High Step-up DC-DC Converter for PMSM Drive ApplicationsIJMTST Journal
In this concept novel high step-up dc–dc converter with an active coupled-inductor network is presented for
a sustainable energy system. The proposed converter contains two coupled inductors which can be
integrated into one magnetic core and two switches. The primary sides of coupled inductors are charged in
parallel by the input source, and both the coupled inductors are discharged in series with the input source to
achieve the high step-up voltage gain with appropriate duty ratio, respectively. In addition, the passive
lossless clamped circuit not only recycles leakage energies of the coupled inductor to improve efficiency but
also alleviates large voltage spike to limit the voltage stresses of the main switches. The reverse-recovery
problem of the output diode is also alleviated by the leakage inductor and the lower part count is needed;
therefore, the power conversion efficiency can be further upgraded. The voltage conversion ratios, the effect of
the leakage inductance and the parasitic parameters on the voltage gain are discussed. The voltage stress
and current stress on the power devices are illustrated and the comparisons between the proposed converter
and other converters are given. The simulation results are presented by using Mat lab/Simulink software.
Research Inventy : International Journal of Engineering and Scienceresearchinventy
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
This paper presents the detail circuitry modeling of single phase off-grid inverter for small standalone system applications. The entire model is developed in MATLAB/Simulink platform using circuitry model. This off grid inverter consists of a high frequency DC-DC step up converter cascaded with a full bridge PI control voltage source inverter using SPWM modulation with LC filter to produce sine wave output. This is a common design used in many small commercial off-grid inverter. This off-grid inverter model is capable to produce AC sinewave output voltage at 230 V 50 Hz up to 1 kW power from a 48 V DC lead acid battery source. The AC sine wave output waveform achieved a voltage Total Harmonic Distortion (THD) of less than 1 % which is almost a pure sine wave. The conversion efficiency performance of the off-grid inverter achieved more than 94 %. The performance of the model is validated by real commercial off-grid inverter. The performance validation experiment shows that the off-grid inverter Simulink model conversion efficiency and THD performance are comparable to the commercial off-grid inverter. This model contributes to assist small to medium standalone system load and battery sizing design with greater accuracy.
These days we have an increased number of heart diseases including increased risk of heart attacks. Our proposed system users sensors that allow to detect heart rate of a person using heartbeat sensing even if the person is at home. The sensor is then interfaced to a microcontroller that allows checking heart rate readings and transmitting them over internet. The user may set the high as well as low levels of heart beat limit. After setting these limits, the system starts monitoring and as soon as patient heart beat goes above a certain limit, the system sends an alert to the controller which then transmits this over the internet and alerts the doctors as well as concerned users. Also the system alerts for lower heartbeats. Whenever the user logs on for monitoring, the system also displays the live heart rate of the patient. Thus concerned ones may monitor heart rate as well get an alert of heart attack to the patient immediately from anywhere and the person can be saved on time.This value will continue to grow if no proper solution is found. Internet of Things (IoT) technology developments allows humans to control a variety of high-tech equipment in our daily lives. One of these is the ease of checking health using gadgets, either a phone, tablet or laptop. we mainly focused on the safety measures for both driver and vehicle by using three types of sensors: Heartbeat sensor, Traffic light sensor and Level sensor. Heartbeat sensor is used to monitor heartbeat rate of the driver constantly and prevents from the accidents by controlling through IOT.
ABSTRACT The success of the cloud computing paradigm is due to its on-demand, self-service, and pay-by-use nature. Public key encryption with keyword search applies only to the certain circumstances that keyword cipher text can only be retrieved by a specific user and only supports single-keyword matching. In the existing searchable encryption schemes, either the communication mode is one-to-one, or only single-keyword search is supported. This paper proposes a searchable encryption that is based on attributes and supports multi-keyword search. Searchable encryption is a primitive, which not only protects data privacy of data owners but also enables data users to search over the encrypted data. Most existing searchable encryption schemes are in the single-user setting. There are only few schemes in the multiple data users setting, i.e., encrypted data sharing. Among these schemes, most of the early techniques depend on a trusted third party with interactive search protocols or need cumbersome key management. To remedy the defects, the most recent approaches borrow ideas from attribute-based encryption to enable attribute-based keyword search (ABKS
Cloud computing is the one of the emerging techniques to process the big data. Large collection of set or large
volume of data is known as big data. Processing of big data (MRI images and DICOM images) normally takes
more time compare with other data. The main tasks such as handling big data can be solved by using the concepts
of hadoop. Enhancing the hadoop concept it will help the user to process the large set of images or data. The
Advanced Hadoop Distributed File System (AHDF) and MapReduce are the two default main functions which
are used to enhance hadoop. HDF method is a hadoop file storing system, which is used for storing and retrieving
the data. MapReduce is the combinations of two functions namely maps and reduce. Map is the process of
splitting the inputs and reduce is the process of integrating the output of map’s input. Recently, in medical fields
the experienced problems like machine failure and fault tolerance while processing the result for the scanned
data. A unique optimized time scheduling algorithm, called Advanced Dynamic Handover Reduce Function
(ADHRF) algorithm is introduced in the reduce function. Enhancement of hadoop and cloud introduction of
ADHRF helps to overcome the processing risks, to get optimized result with less waiting time and reduction in
error percentage of the output image
Text mining has turned out to be one of the in vogue handle that has been joined in a few research
fields, for example, computational etymology, Information Retrieval (IR) and data mining. Natural
Language Processing (NLP) methods were utilized to extricate learning from the textual text that is
composed by people. Text mining peruses an unstructured form of data to give important
information designs in a most brief day and age. Long range interpersonal communication locales
are an awesome wellspring of correspondence as the vast majority of the general population in this
day and age utilize these destinations in their everyday lives to keep associated with each other. It
turns into a typical practice to not compose a sentence with remedy punctuation and spelling. This
training may prompt various types of ambiguities like lexical, syntactic, and semantic and because of
this kind of indistinct data; it is elusive out the genuine data arrange. As needs be, we are directing
an examination with the point of searching for various text mining techniques to get different
textual requests via web-based networking media sites. This review expects to depict how
contemplates in online networking have utilized text investigation and text mining methods to
identify the key topics in the data. This study concentrated on examining the text mining
contemplates identified with Facebook and Twitter; the two prevailing web-based social networking
on the planet. Aftereffects of this overview can fill in as the baselines for future text mining research.
Colorectal cancer (CRC) has potential to spread within the peritoneal cavity, and this transcoelomic
dissemination is termed “peritoneal metastases” (PM).The aim of this article was to summarise the current
evidence regarding CRC patients at high risk of PM. Colorectal cancer is the second most common cause of cancer
death in the UK. Prompt investigation of suspicious symptoms is important, but there is increasing evidence that
screening for the disease can produce significant reductions in mortality.High quality surgery is of paramount
importance in achieving good outcomes, particularly in rectal cancer, but adjuvant radiotherapy and chemotherapy
have important parts to play. The treatment of advanced disease is still essentially palliative, although surgery for
limited hepatic metastases may be curative in a small proportion of patients.
Heat transfer in pipes is a distinctive kind of procedure employed in heat exchanger which transfers great
deal of heat because of the impact of capillary action and phase change heat transfer principle. Late improvement
in the heat pipe incorporates high thermal conductivity liquids like Nano liquids, fixed inside to extricate the most
extreme heat. This paper audits, impact of different factors, for example, thermal pipe tilt edge, charged measure
of working liquid, nano particles sort, size, and mass/volume part and its impact on the change of thermal
proficiency, thermal exchange limit and decrease in thermal protection. The Nano liquid arrangement and the
examination of its thermal attributes likewise have been investigated. The retained sun oriented vitality is
exchanged to the working liquid streaming in the pipe. The execution of the framework is affected by thermal
exchange from tube to working liquid, with least convective misfortunes, which must be considered as one of the
essential plan factor. In tube and channel streams, to improve the rate of heat exchange to the working liquid,
detached enlargement methods, for example, contorted tapes and swirl generators are employed from the fluid
flow path. The variation of heat transfer coefficient and pressure drop in the pipe flow for water and water based
Al2O3 Nano fluids at different volume concentrations and twisted tapes are studied.
Now-a-day’s pedal powered grinding machine is used only for grinding purpose. Also, it requires lots of efforts
and limited for single application use. Another problem in existing model is that it consumed more time and also has
lower efficiency. Our aim is to design a human powered grinding machine which can also be used for many purposes
like pumping, grinding, washing, cutting, etc. it can carry water to a height 8 meter and produces 4 ampere of electricity
in most effective way. The system is also useful for the health conscious work out purpose. The purpose of this technical
study is to increase the performance and output capacity of pedal powered grinding machine.
This project proposes a distributed control approach to coordinate multiple energy storage units
(ESUs) to avoid violation of voltage and network load constraints ESU as a buffer can be a promising
solution which can store surplus power during the peak generation periods and use it in peak load
periods.In ESU converters both active and reactive power are used to deal with the power quality
issues in distribution network ESU’s reactive power is proposed to be used for voltage support, while
the active power is to be utilized in managing network loading.
The steady increase in non-linear loads on the power supply network such as, AC variable speed drives,
DC variable Speed drives, UPS, Inverter and SMPS raises issues about power quality and reliability. In this
subject, attention has been focused on harmonics . Harmonics overload the power system network and cause
reliability problems on equipment and system and also waste energy. Passive and active harmonic filters are
used to mitigate harmonic problems. The use of both active and passive filter is justified to mitigate the
harmonics. The difficulty for practicing engineers is to select and deploy correct harmonic filters , This paper
explains which solutions are suitable when it comes to choosing active and passive harmonic filters and also
explains the mistakes need to be avoided.
This Paper is aimed at analyzing the few important Power System equipment failures generally
occurring in the Industrial Power Distribution system. Many such general problems if not resolved it may
lead to huge production stoppage and unforeseen equipment damages. We can improve the reliability of
Power system by simply applying the problem solving tool for every case study and finding out the root cause
of the problem, validation of root cause and elimination by corrective measures. This problem solving
approach to be practiced by every day to improve the power system reliability. This paper will throw the light
and will be a guide for the Practicing Electrical Engineers to find out the solution for every problem which
they come across in their day to day maintenance activity.
More from IJET - International Journal of Engineering and Techniques (20)
Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxR&R Consult
CFD analysis is incredibly effective at solving mysteries and improving the performance of complex systems!
Here's a great example: At a large natural gas-fired power plant, where they use waste heat to generate steam and energy, they were puzzled that their boiler wasn't producing as much steam as expected.
R&R and Tetra Engineering Group Inc. were asked to solve the issue with reduced steam production.
An inspection had shown that a significant amount of hot flue gas was bypassing the boiler tubes, where the heat was supposed to be transferred.
R&R Consult conducted a CFD analysis, which revealed that 6.3% of the flue gas was bypassing the boiler tubes without transferring heat. The analysis also showed that the flue gas was instead being directed along the sides of the boiler and between the modules that were supposed to capture the heat. This was the cause of the reduced performance.
Based on our results, Tetra Engineering installed covering plates to reduce the bypass flow. This improved the boiler's performance and increased electricity production.
It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
[IJET- V2I2P17] Authors: Gaurav B. Patil., Paresh J. Shah
1. International Journal of Engineering and Techniques - Volume 2 Issue 2, Mar – Apr 2016
ISSN: 2395-1303 http://www.ijetjournal.org Page 100
A Review on Single Stage Forward and Fly back Converter to
Improve its Performance
Gaurav B. Patil.1
, Paresh J. Shah.2
1(PG Scholar of Electrical Department, SSBT College, Jalgaon)
2 (Head of Electrical Department, SSBT College, Jalgaon)
I. INTRODUCTION
Recently power converters either AC-AC or DC-
DC are broadly used in a high and low Power
application. Traditionally, these AC-DC converters
are mostly consist of two stages. In the first stage,
AC voltage is converted into an uncontrolled DC
voltage using Diode and rectifiers, which gives its
output second stage of isolated DC-DC converters
as input using HF transformer for isolation. These
two-stage AC-DC converters have the problems of
power quality in terms of injected harmonic
currents at AC mains, caused voltage distortion,
degraded power factor, high crest factor, and large
size of DC capacitor filter at first stage. Though all
these concern are considered. Modern AC-DC
converters are being developed in single-stage to
improve power quality, reduced number of
components and high efficiency. These problems
can be avoided using newly developed single-stage
enhanced power quality AC-DC converters using
transformer isolation. They are also known as input
current shapers, high power-factor single-stage
converters, power factor correction (PFC)
converters; universal input single-stage PFC
isolated converters.
This paper deals with overview of enhanced
topologies of AC-DC converter with isolation. All
these enhanced single stage AC-DC converters with
isolation are generally classified.
Fig.1 Classification of AC-DC Converter
Fig. 1 shows the classification isolated single-phase
AC-DC converter. The enhanced power quality
AC-DC converters feed from single-phase AC
mains is classified into three major categories,
namely, buck, boost, and buck-boost topologies. All
these three types of converters are further classified
into four types of configurations. Some of these
converters are also known as single-phase, single-
stage converter or single-stage single-switch
converter).
Normally, fly back converter have good
power factor but having issues with high offset
current through the transformer magnetizing
Inductor, large core losses and low power
conversion efficiency. Whereas forward converter
can achieve good power conversion efficiency with
low core loss. They have low power factor. All
RESEARCH ARTICLE OPEN ACCESS
Abstract:
Universal demand for power increases due to continuous development to fulfil all these demand. Resources
are used with optimization. A high efficiency and high power factor converters are the major parts of energy
transfer system. This paper present a general review on single stage forward and flyback converter topologies to get
better its performance. This is paper presents a kind general idea of increasing efficiency and power factor of single
stage forward and fly back converter.
Keywords — Forward-Fly back, MOSFET, PFC, THD
2. International Journal of Engineering and Techniques - Volume 2 Issue 2, Mar – Apr 2016
ISSN: 2395-1303 http://www.ijetjournal.org Page 101
these limitations can be achieved by combining
both topologies in same package.
II. LITRATURE REVIEW
In this paper, a high efficiency and high power
factor single-stage balanced forward-flyback
converter merging a forward and fly back converter
topologies is studied. The conventional AC/DC fly
back converter can achieve a good power factor but
it has a high offset current through the transformer
magnetizing inductor, which results in a large core
loss and low power conversion efficiency. And, the
conventional forward converter can achieve the
good power conversion efficiency with the aid of
the low core loss but the input current dead zone
near zero cross AC input voltage deteriorates the
power factor. On the other hand, since the proposed
converter can operate as the forward and fly back
converters during switch on and off periods,
respectively, it cannot only perform the power
transfer during an entire switching period but also
achieve the high power factor due to the fly back
operation. Moreover, since the current balanced
capacitor can minimize the offset current through
the transformer magnetizing inductor regardless of
the AC input voltage, the core loss and volume of
the transformer can be minimized. Therefore, the
proposed converter features a high efficiency and
high power factor. To confirm the validity of the
proposed converter, theoretical analysis and
experimental results from a prototype of 24W LED
driver are presented. [1, 3]
Fly-back converters have been widely used
because of the irrelative simplicity and their
excellent performance for multi output applications.
They can save cost and volume compared with the
other converters, especially in moderate low power
applications. In a fly-back converter, a transformer
is adopted to achieve galvanic isolation and energy
storage. [2]
Global energy consumption tends to grow
continuously. To satisfy the demand for electric
power against a background of the depletion of
conventional, fossil resources the renewable energy
sources are becoming more popular. According to
the researches despite its fluctuating nature and
weather dependency the capacity of renewable
resources can satisfy overall universal demand for
power. High gain DC/DC converters are the key
part of renewable energy systems .The designing of
high gain DC/DC converters is compulsory by
severe demands. The power conditioning systems
for the photovoltaic power sources needs high step-
up voltage gain due to the low output of the
generating sources. A high step-up topology
employing a Series-connected Forward-Fly Back
converter, which has a series-connected output for
high boost voltage-transfer gain. Series-connected
Forward-Fly Back converter is a hybrid type of
forward and fly back converter. By stacking the
outputs of them extremely high voltage gain can be
obtained with small volume and high efficiency
with a galvanic isolation. The separated secondary
windings reduce the voltage stress of the secondary
rectifiers and results in high efficiency.[4]
In order to reduce output voltage ripple, it is
a common practice to place a large electrolytic
capacitor at the output of the conventional, single
phase capacitive rectifier. This results in power
converter with poor power factor and high total
harmonic distortion (THD). In recent years, many
high frequency power factor correction (PFC)
circuits and current shaping control techniques were
developed to meet certain standards. [5]
The Fly back converter can both step up and
step-down the input voltage, while maintaining the
same polarity and the same ground reference for the
input and output. MOSFETs are used as a switching
device in low power and high frequency switching
applications. It may be noted that, as the turn-on
and turn-off time of MOSFETs are lower as
compared to other switching devices, which reduces
the switching losses. High frequency operation of
MOSFET reduced size of filters components. These
converters are now being used for various
applications, such as Switched Mode Power Supply
(SMPS) etc. Due to designing and tuning of Fly
back converters it can be used to designing of an
optimized controller for isolated DC-DC Fly back
converter for constant voltage applications. [6]
The Zero Voltage Switching (ZVS)
technique is used to achieve soft switching. A
bidirectional boost converter is connected with an
output module as a Parallel Input Serial Output
configuration. The flyback converter with Voltage
Doubler Rectifier (VDR) acts as an output module.
3. International Journal of Engineering and Techniques - Volume 2 Issue 2, Mar – Apr 2016
ISSN: 2395-1303 http://www.ijetjournal.org Page 102
This connection makes a bidirectional boost
converter an active clamp circuit which is
connected to the output side in order to extend the
step up ratio. A converter with active clamp
technique is used to recycle the leakage energy, to
eliminate voltage spike due to coupled inductors
and also to provide a mechanism to achieve ZVS.
To overcome the efficiency degradation during
light load due to load dependent soft switching of
the ZVS, a control method using Pulse Width
Modulation (PWM) proportional to the load current
is used.[7]
A zero-voltage switching (ZVS) forward-
flyback DC-DC converter, which is able to process
and deliver power efficiently over a wide input
voltage variation. The converter operates at
boundary mode between current continuous and
discontinuous mode to achieve ZVS. Variable
frequency with fixed off time is used for reducing
core losses of the transformer, achieving high
efficiency.[10]
A new bridgeless buck PFC rectifier that
substantially improves efficiency at low line of the
universal line range is introduced. By eliminating
input bridge diodes, the proposed rectifier’s
efficiency is further improved. Moreover, the
rectifier doubles its output voltage, which extends
useable energy of the bulk capacitor after a drop-
out of the line voltage.[9]
III. CONCEPT OF FLY BACK CONVERTER
Fly-back converter is the most commonly used
SMPS circuit for low output power applications
where the output voltage needs to be isolated from
the input main supply. The output power of fly-
back type SMPS circuits may vary from few watts
to less than 100 watts. The overall circuit topology
of this converter is considerably simpler than other
SMPS circuits. Input to the circuit is generally
unregulated dc voltage obtained by rectifying the
utility ac voltage followed by a simple capacitor
filter. The circuit can offer single or multiple
isolated output voltages and can operate over wide
range of input voltage variation. In respect of
energy-efficiency, fly-back power supplies are
inferior to many other SMPS circuits but its simple
topology and low cost makes it popular in low
output power range. The commonly used fly-back
converter requires a single controllable switch like,
MOSFET and the usual switching frequency is in
the range of 100 kHz. A two-switch topology exists
that offers better energy efficiency and less voltage
stress across the switches but costs more and the
circuit complexity also increases slightly. The
present lesson is limited to the study of fly-back
circuit of single switch topology. Fig.2 shows the
basic topology of a fly-back circuit. Input to the
circuit may be unregulated dc voltage derived from
the utility ac supply after rectification and some
filtering. The ripple in dc voltage waveform is
generally of low frequency and the overall ripple
voltage waveform repeats at twice the ac mains
frequency.
Fig.2. Basic Topology of Fly-Back Converter.
Since the SMPS circuit is operated at much
higher frequency (in the range of 100 kHz) the
input voltage, in spite of being unregulated, may be
considered to have a constant magnitude during any
high frequency cycle. A fast switching device („S‟),
like a MOSFET, is used with fast dynamic control
over switch duty ratio (ratio of ON time to
switching time-period) to maintain the desired
output voltage. The transformer, in Fig.2, is used
for voltage isolation as well as for better matching
between input and output voltage and current
requirements.
IV. CONCEPT OF FORWARD CONVERTER
Forward converter is another popular switched
mode power supply (SMPS) circuit that is used for
producing isolated and controlled dc voltage from
the unregulated dc input supply. The forward
converter, when compared with the fly-back circuit,
4. International Journal of Engineering and Techniques - Volume 2 Issue 2, Mar – Apr 2016
ISSN: 2395-1303 http://www.ijetjournal.org Page 103
is generally more energy efficient and is used for
applications requiring little higher power output (in
the range of 100 watts to 200 watts). However the
circuit topology, especially the output filtering
circuit is not as simple as in the fly-back converter
Fig.3 shows the basic topology of the forward
converter. It consists of a fast switching device ‘S’
along with its control circuitry, a transformer with
its primary winding connected in series with switch
‘S’ to the input supply and a rectification and
filtering circuit for the transformer secondary
winding. The load is connected across the rectified
output of the transformer-secondary.
Fig.3. Basic forward converter topology
The transformer used in the forward converter is
to be an ideal transformer with no leakage fluxes,
zero magnetizing current and no losses. The basic
operation of the circuit is explained with different
mode operation here assuming ideal circuit
elements. In fact, due to the presence of finite
magnetizing current in a practical transformer,
tertiary winding needs to be introduced in the
transformer and the circuit topology changes
slightly.
V. SINGLE SWITCH CONVERTER
PFC circuit can be available in two forms, i.e.
single stage and two –stage scheme in two stage
schemes. In two stage scheme, AC-DC converter is
connected to the line to provide good input power
factor and generate regulated dc voltage. Generally
this voltage cannot directly supply the load since it
contains intolerable second harmonic content.
Therefore a ac/dc converter is cascade to tightly
regulate the output voltage. These two power stages
are controlled separately. And thus it makes
optimization of both converters possible. The main
drawbacks of this scheme are its higher cost and
larger size resulting from its increased component
number and complicated control circuits. The one –
stage PFC scheme combines the PFC circuit and the
voltage regulation circuit in one stage. Due to the
simplified power stage and control circuit of the
single stage scheme, it is attractive to many
applications with cost size.
Fig. 4. InputV-I characteristics of basic flyback converter
operating in DCM.
(a) Flyback converter in PFC application.
(b) Input current. (c) Input V-I characteristics.
Fig.5. Basic circuit schematic of proposed converter.
The isolated flyback converter circuit and its
input current waveform are shown in Fig. 4. (a) and
(b), respectively.[5] Since switching frequency, it is
reasonable to assume that the line voltage is
constant in a switching cycle.
The basic circuit schematic of proposed new
single stage single switch isolated converter is
shown in Fig.5.[5] The input circuit employs a
Flyback topology and the output circuit is a forward
converter. The power switch and storage capacitor
5. International Journal of Engineering and Techniques
ISSN: 2395-1303
are placed between the two circuits with diode D1
and D2 coordinating their two separate operations.
Table 1. Time intervals and staus of devices in
mode operation
Mode Time
interval
Conducting device
S D
1
D
2
D
3
M1 to<t<t1 × ×
M2 t1≤t≤t’2 × ×
t'2≤t≤t2 ×
M3 t2≤t≤to
+Ts
It can be shown that in steady state the converter
operates in three operation modes du
switching cycle. Table1. Shows three modes of
operations. According to corresponding times and
the status of the switching devices.
Fig.6. Theoretical key waveforms of proposed
converter.
Typical steady state operation waveforms are
shown in fig. 6. Which consist of three modes can
be deeply studied with table1 having output filter
maintains the output voltage until next switching
cycle begins. Considering all design parameters i.e.
maximum duty ratio, magnetizing inductance,
transform ratio, selection of capacitor, filter
inductance, power switch and diodes. The
waveforms of filtered line current, switch voltage
and current through diodes D1 were recorded at
International Journal of Engineering and Techniques - Volume 2 Issue 2, Mar –
http://www.ijetjournal.org
laced between the two circuits with diode D1
and D2 coordinating their two separate operations.
Table 1. Time intervals and staus of devices in
Conducting device
D
4
D
5
×
×
×
×
It can be shown that in steady state the converter
operates in three operation modes during one
three modes of
corresponding times and
. Theoretical key waveforms of proposed
on waveforms are
. Which consist of three modes can
be deeply studied with table1 having output filter
til next switching
cycle begins. Considering all design parameters i.e.
maximum duty ratio, magnetizing inductance,
transform ratio, selection of capacitor, filter
inductance, power switch and diodes. The
waveforms of filtered line current, switch voltage
and current through diodes D1 were recorded at
peak line voltage. It is found that simulated and
experimental waveforms are in a good agreement.
The line current waveforms are
and in phase with the line voltage, proving that
good power factor was achieved by this converter
topology. Fig.7. represents measu
and efficiency under different load condition.
(a) Input power factor
(b)Efficiency
Fig.7. Experimental efficiency and input power factor.
VI. Conventional single stage PFC converter
Recently, conventional single-
factor correction) LED drivers
which are well known as most cost
solutions. Fig.9. shows their transformer
magnetizing inductor currents. As shown in this
figure, the magnetizing inductor offset current of
fly back converter is larger than that of forward
– Apr 2016
Page 104
peak line voltage. It is found that simulated and
experimental waveforms are in a good agreement.
waveforms are almost sinusoidal
and in phase with the line voltage, proving that
ctor was achieved by this converter
asured power factor
and efficiency under different load condition.
(a) Input power factor
efficiency and input power factor.
Conventional single stage PFC converter
-stage PFC (power
factor correction) LED drivers shown in fig. 8,
which are well known as most cost effective
shows their transformer
magnetizing inductor currents. As shown in this
figure, the magnetizing inductor offset current of
fly back converter is larger than that of forward
6. International Journal of Engineering and Techniques - Volume 2 Issue 2, Mar – Apr 2016
ISSN: 2395-1303 http://www.ijetjournal.org Page 105
converter. The magnetizing inductor offset current
of fly back and forward converter is
< , >=
˳
( )
(1)
< , >= 1 + !
"#
$%&
'^2*+
(2)
(a) Single-stage flyback converter
(a) Single stage forward converter
Fig 8 Conventional single stage PFC converter circuits
Moreover, from equations (1) and (2), while the
magnetizing inductor offset current of flyback
converter is dependent on the load current Io, that
of forward converter is not. Therefore, as the load
current is more increased, the offset current of
flyback converter becomes larger, which might
result in the larger core loss and volume of
transformer. For these reasons, the forward
converter is superior to the flyback converter in
terms of the transformer size and energy conversion
efficiency.
Fig.9. Transformer magnetizing inductor currents of
conventional flyback and forward converters
Fig 10.PFC performance of forward and flyback
In the meanwhile, as shown in Fig. 10, while the
flyback converter can transfer the input energy to
the output side over an entire range of input
voltage, the forward converter cannot at the lower
input voltage than the reflected output voltage nVo
to the transformer primary side. This is because the
forward converter is originated from the step-down
buck topology. Therefore, the input current dead
zone near zero cross AC input voltage is always
observed and deteriorates the power factor in the
forward converter. Therefore, the flyback converter
is superior to the forward converter in terms of the
PFC performance.
7. International Journal of Engineering and Techniques - Volume 2 Issue 2, Mar – Apr 2016
ISSN: 2395-1303 http://www.ijetjournal.org Page 106
VII. Proposed single stage PFC forward flyback
converter
To solve all these problems, a high efficiency and
high power factor single-stage balanced forward-
flyback converter is proposed as shown in Fig.11.
Since the proposed converter merges the forward
and flyback topologies, it can operate as the
forward and flyback converters during switch turn-
on and off periods, respectively. Therefore, it
cannot only perform the power transfer during an
entire switching period but also achieve the high
power factor. Especially, since the charge balanced
capacitor Cb can make the proposed converter
perform the forward operation regardless of the
input voltage, the magnetizing inductor offset
current, core loss and transformer size can be
minimized.
Fig.11. Proposed single stage PFC forward flyback converter
circuit
Fig. 11 shows the circuit diagram of the proposed
forward flyback converter.[1] As shown in this
figure, its primary side is exactly same as that of the
conventional flyback converter consisting of one
power switch (M1) and one transformer. On the
other hand, its secondary side consists of one output
inductor (Lo) for forward operation, one DC
blocking capacitor (Cb) for balancing operation and
three output Diodes (D1, D2, D3). When M1 is
conducting, the proposed converter operates as a
forward converter. On the other hand, when M1 is
blocked, the proposed converter operates as a
flyback converter. However, if it is assumed that
the proposed converter has no balancing capacitor
Cb, abovementioned forward operation is possible
only when the reflected primary voltage Vin/n to
the transformer secondary side is higher than the
output voltage Vo. This is because the forward
converter is originated from the buck converter.
Therefore, the forward-flyback converter operates
only as a flyback converter over the range of Vin/n
< Vo. Especially, at the minimum input voltage
near Vin=90Vrms, Vin/n is lower than Vo during
most of periods and thus, the transformer has a
large magnetizing offset current similar to the
conventional flyback converter. In this case, the
transformer core loss and volume are also as large
as those of the conventional flyback converter. On
the other hand, if the balancing capacitor Cb is
serially inserted with the transformer secondary
side, it can make the average current through Cb
during forward operation become exactly same as
that during flyback operation by the charge balance
principle of Cb. In other words, since the voltage
across Cb charged by flyback operation is added to
the Vsec=Vin/n during forward operation,
Vin/n+Vcb becomes higher than Vo and thus, the
forward operation is possible even at Vin/n<Vo
(a) (b)
Fig.12. Primary and magnetizing currents of forward-flyback
converter according to the input voltage. (a) Without
balancing capacitor (b) with balancing capacitor
Therefore, the proposed forward-flyback converter
with the balancing capacitor Cb can always operate
as both forward and flyback converters regardless
of the input voltage.
Fig.12. shows the primary and magnetizing current
waveforms of the proposed converter operating in
the boundary conduction mode (BCM). And, Fig.12
(a) and (b) show current waveforms without and
with balancing capacitor Cb according to the input
voltage, respectively. As mentioned earlier, the
proposed converter with Cb can operate as both
forward and flyback converters over an entire range
of input voltage with the aid of Vcb. On the other
8. International Journal of Engineering and Techniques - Volume 2 Issue 2, Mar – Apr 2016
ISSN: 2395-1303 http://www.ijetjournal.org Page 107
hand, while the proposed converter without Cb can
transfer the input energy to the output side at
Vin/n>Vo, it cannot at Vin/n<Vo. As a result, the
proposed converter with balancing capacitor Cb
features a smaller magnetizing offset current,
resultant smaller core loss and more reduced
transformer volume.
Fig.13. Key waveforms of the proposed forward – flyback
converter
The circuit operation of the proposed converter is
basically divided into two modes according to the
conduction state of each switch as shown in fig.13.
first mode operation from time interval t0-t1 and
second from t1-t2. By considering all design
parameters regarding proposed converter its
performance is observed. Which also compared
with conventional proposed individual converters
and analysis conclude that it is suitable for low
power application. For experimental performance
of converter it’s operated with different root mean
square values of voltage and efficiency and power
factor is observed.
Fig.14. Comparisons of efficiency and power factor between
flyback and proposed forward-flyback converter
Fig. 14 shows the measured efficiency and power
factor of the proposed forward-flyback and
conventional flyback converters. As shown in this
figure, the proposed converter has the high power
factor above 95% over a wide range of input
voltage. Especially, its efficiency along wide input
voltage range is above 88.71% and higher than the
conventional converter by maximum 8.07% at
264Vrms. This high efficiency is due primarily to
the small transformer offset current and resultant
reduced core loss.
VIII. CONCLUSION
This paper discusses various topologies employed
for improvement of performance AC-DC converter.
Initially conventional forward flyback converter
uses two Transformers. This is having problems
regarding size and cost due to large number circuit
component. In order to overcome these drawbacks
of two stage scheme. One stage PFC scheme
adopted which combines fly back and forward
circuit in single stage it makes optimization of
converter in single package. Another issues of
magnetizing offset current , core loss are overcome
with single stage balanced forward –flyback type
proposed converter .which have current balanced
capacitor can minimize the offset current all the
way through the transformer magnetizing inductor
apart from input AC voltage and reduce core loss.
After this review we realized that single stage
9. International Journal of Engineering and Techniques - Volume 2 Issue 2, Mar – Apr 2016
ISSN: 2395-1303 http://www.ijetjournal.org Page 108
scheme is outstanding solution for low power
application. It also provides good power factor and
efficiency.
REFERENCES
[1] Yoon choi, Moon- Keum and Sang Kyoohan
,jeong-ilkang, “ High efficiency and High Power
Factor Single Stage Balanced Forward – Fly back
Converter”, Proceeding of the IEEE, pp. 822-827,
2013.
[2] Subhrajyoti Modak , Goutam Kumar Panda,
Pradip Kumar Saha and Sanskar Das , “Design of
Novel fly-back converter using PID controller”
Proceeding of IJAREEIE, Vol.4, pp. 289-297,Jan
2015.
[3] M. Venkatesh Kumar and K. Chandra, “Power
Factor Improvement using Single Stage Balanced
Forward Flyback Converter” Proceeding of IJIT,
Vol.3, No.4, pp. 640-645, July 2015.
[4] J. Lee, J. Park, H. Jeon, “Series-Connected
Forward–Flyback Converter for High Step-Up
Power Conversion,” IEEE Trans. Power
Electronics, Vol.26, No.12, pp.3629-3641, Dec.
2011.
[5] Hua-Min Xu, Xin-Bo Ruan, Yang-Guang Yan “
A Novel Forward Single-Stage Single-Switch
Power Factor Correction AC/DC converter”,
Proceeding of PESC, Vol.2, pp. 754-759, 2001.
[6] Abhinav Dogra, Kanchan pal, “Designing and
Tuning of PI Controller for Flyback Converter”,
Proceeding of IJETT, Vol. 13 No.3, Jul 2014.
[7] R. Sudha and P.M. Dhanasekaran, “DC—DC
Converter Using PID Controller and Pulse Width
Modulation Technique”, Proceeding of IJETT,
Vol.7, No.4, pp165-168, Jan 2014.
[8] Yonghan Kang, Byungcho Choi and Wonseok
Lim, "Analysis and Design of a Forward-Flyback
Converter Employing Two Transformers",
Proceeding of the IEEE, Vol. 1, pp. 357-362, June.
2001.
[9] Yungtaek Jang and Milan M. Jovanovic,
"Bridgeless Buck PFC Rectifier", Proceeding of the
APEC2010, pp. 23-29, Feb. 2010.
[10] F. Chen, E. Auadisian, J. Shen and I. Batarseh,
"Soft switching Forward-Flyback DC-DC
Converter", Proceeding of JECE, Vol.3, No.5, pp.
26-35, 2013.
[11] Sanjeevsingh and Bhimsingh,“ Comprehensive
study of single phase AC-DC power corrected
converter with High frequency isolation” ,IEEE
trans. On Industrial Informatics, Vol. 7, No. 4, pp.
540-556, Nov 2011.