EPE Association: EPE 2009 - Subtopic 04-4 - DS: 'Soft Switch Converters'

EPE 2009 - Subtopic 04-4 - DS: 'Soft Switch Converters'
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2009 - Conference > EPE 2009 - Topic 04: 'Soft Switch Converters' > EPE 2009 - Subtopic 04-4 - DS: 'Soft Switch Converters'

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   A High Frequency Planar Transformer-linked ZVS DCâ€“DC Converter with Secondary-side Phase-Shifting PWM Rectifier
By Tomokazu MISHIMA, Yuji YOSHIZAKO, Mutsuo NAKAOKA [View]
[Download]

Abstract: This paper presents a feasibility study of a zero voltage switching (ZVS) PWM full bridge (FB) DC-DC converter with high-frequency planar transformer-link. The soft-switching PWM FB DC-DC converter newly-developed for a switching power amplifier in a plasma generator can achieve soft commutations in switching power devices under the wide range of load power. Moreover, it can attain the effective reduction of idling power due to the phase-shift PWM scheme. In this paper, the essential experimental data obtained from a 100kHz -8kW prototype is described to demonstrate the practical effectiveness of the ZVS-PWM FB DC-DC converter.

   A High-Voltage Parallel Resonant Converter with single capacitor as an output filter
By Juan DIAZ, Juan A. MARTIN-RAMOS, Alberto MARTIN-PERNIA, Juan A. MARTINEZ, Pedro J. VILLEGAS [View]
[Download]

Abstract: High-voltage converters have to keep large distances between primary and secondary, and also they use a large number of turns at the secondary side. For these reasons, an HV transformer usually has parastic elements that can not be neglected. The topologies have to cope with this extra components and it is desirable to include them in the topology. In fact, the serial resonant converter includes the leakage inductance, as well as the Parallel Resonant Converter, the PRC. This one includes also the parallel capacitor. In this paper, the PRC steady state modelling and experimental results are presented.

   A Motor-Friendly and Efficient Resonant DC-Link Converter
By Calin PURCAREA, Jayalakshmi KEDARISETTI, Peter MUTSCHLER [View]
[Download]

Abstract: Parasitic high frequency (HF) phenomena for adjustable speed drives (ASD) fed by inverters with fast switching semiconductors are well known in literature. Although many advantages rise when using higher switching frequencies, like lower motor harmonics and audible noise, feeding the electrical machine through long cables lead to high voltage overshoots at motor terminals due to cable-motor impedance mismatch. Another important aspect in power converter design represents the efficiency, which has to be as high as possible. In this paper two topologies of resonant DC-link converter proving in the same time high efficient and motor-friendly are analyzed. Principle of operation are discussed together with control strategy and design. Motor-friendly characteristics are presented. Finally, simulations and measurements back up the reliability of chosen topology.

   A Push-Pull Converter Based Bidirectional DC-DC Interface for Energy Storage Systems
By Eiji HIRAKI, Kazumasa HIRAO, Toshihiko TANAKA, Mishima TOMOKAZU [View]
[Download]

Abstract: In recent years, power electronic energy storage systems using super capacitor bank have been widely studied and developed for the electronic vehicles. In this paper, a full-bridge/centertapped push-pull circuit with active clamp-based soft switching bidirectional DC-DC converter and its control method are presented and discussed. From the results of basic experimental demonstration, the proposed system is able to perform adequate charging and discharging operation between low-voltage high-current super capacitor side and high-voltage low-current side with drive train and main battery. In addition, RCDi snubber losses appeared in the basic circuit topology are drastically reduced by ZCS/ZVS operation with the assistance of newly added active clump circuit, as well as ZVS operation with lossless snubber capacitor in high-voltage primary side.

   A Zero-Current-Switch Quasi-Resonant Boost Converter with Transformer Compensated Clamp Circuit
By Eka FIRMANSYAH, Satoshi TOMIOKA, Seiya ABE, Masahito SHOYAMA, Tamotsu NINOMIYA [View]
[Download]

Abstract: This paper presents a method to prevent voltage ringing on the main switch of a full-wave zero-current-switch quasi-resonant (ZCS-QR) boost converter during its turn-off period. The proposed method does not incorporate any dissipative snubber in order to maintain efficiency of the converter. Severe clamp diode reverse recovery current and non-zero turn-on current occurred on the former diode-clamped ZCS-QR boost topology could be solved by this proposed topology without additional active switch and extra control effort. A detailed working principles and governing equations are explained. Experimental results showing the performance of the proposed converter are also included.

   Alternating Switching of Inductive Decoupled IGBTs in Voltage Source Inverters
By Hans-GÃ¼nter ECKEL, Eberhard KRAFFT [View]
[Download]

Abstract: A new switching scheme for ZVS of inductive decoupled high voltage IGBTs is proposed. Each half bridge, consisting of two IGBT and two diodes, is split into two parallel half-bridges. The outputs of these half-bridges are decoupled by an inductance. An alternating switching scheme leads to hard switching turn-off and zero voltage switching turn-on. The IGBT turn-on losses can be reduced to less than 10\% compared to hard-switching. The reverse recovery stress for the free-wheeling diode determines the size of the decoupÂ¬ling inductor. As the IGBT turn-on and diode reverse-recovery losses are dominating at high voltage IGBT, the output current of the inverter can be significantly increased. In the paper, the different switching schemes for inductive decoupled inverter legs are compared. For the alternating switches scheme, the effect of the diode reverse recovery and the current redistribution during the conduction phases are explained in detail. Experimental results are given for 6.5 kV IGBT, the dependence of the diode reverse recovery stress on different operation parameters is discussed.

   Calorimetric Loss Measurements and Optimisation of High Power Resonant Converters for Pulsed Applications
By Fabio CARASTRO [View]
[Download]

Abstract: This paper considers the calorimetric measurements of losses and the optimisation of high power resonant converters. For the tests a single phase resonant converter rated at 1 kV, 250 A (250 kW peak power, duty ratio 10 \%, 25 kW average power, pulse length 1ms) has been developed. This represents one phase of a multi-phase resonant power supply designed for long-pulse modulation (typically 1 ms to 2 ms) of RF tubes when equipped with a suitable output transformer. Pulsed operation is obtained by direct modulation of the high frequency power supply. The main aim of the work reported here is to calorimetrically monitor semiconductor losses and to experimentally optimise the value of turn-off snubber capacitors across the devices. The paper provides an overview of the technology and design used on the test rig prototype under study. Experimental results and semiconductor losses obtained through calorimetry will be provided to validate the effectiveness of the proposed techniques.

   Comparison of Non-Resonant and Super-Resonant Dual-Active ZVS-Operated High-Power DC/DC Converters
By Robert LENKE, Florian MURA, Rik W. DE DONCKER [View]
[Download]

Abstract: Two bi-directional high-power dc-dc converter topologies with zero-voltage-switching (ZVS) operation over a defined load range are compared. These are the non-resonant dual-active bridge (DAB) and the dual-active series-resonant converter (DSRC) in super-resonant mode. A unified mathematical model describing both converters is presented, which treats the DAB as a boundary case of the super-resonant DSRC with infinite capacitance. It bases on a modification of an existing analytical analysis of the DSRC. Using the model, a method is developed to optimize the ac link transformer size for a limited dynamic voltage operating range with constant power capability, suitable for high-power converters in utility applications. The influence of the resonant capacitor on transformer size and other vital converter characteristics is quantitatively evaluated.

   IMPROVED CIRCUIT OF THE SWITCHED COUPLED-INDUCTOR CELL FOR DC-DC CONVERTERS WITH VERY LARGE CONVERSION RATIO
By Boris AXELROD, Yefim BERKOVICH, Saad TAPUCHI, Adrian IOINOVICI [View]
[Download]

Abstract: By replacing the inductor in a basic boost converter by a multiple-coupled-inductor, and adding two diodes and a capacitor, a new converter with a large conversion ratio and low stresses on the switches is obtained. The additional diode helps to circulate the leakage inductance energy to the load in a non-oscillatory manner. The transistor turns on/off with soft-switching. The diodes turn on with zero-voltage switching and turn off with zero-current-switching, their reverse-recovery problem is alleviated. The voltage stress on both the transistor and diodes is less than the output voltage. Computer simulation and experimental results confirmed the theoretical expectations.

   Improvement for Very High Efficiency Chopper Circuit SAZZ
By Yukinori TSURUTA, Martin PAVLOVSKY, Atsuo KAWAMURA [View]
[Download]

Abstract: The paper describes a study aiming at reaching a very high 99 \% efficiency in DC-DC chopper for electric vehicle (EV) application by improvements of conventional SAZZ topology. Optimisation of the operating frequency and the use multiple parallel SiC diodes were the main improvements of SAZZ chopper that were studied. These led to obtaining the efficiency of 98.96 \% in an 8 kW experimental setup. New, 30 kW fully bi-directional DC-DC converter based on SAZZ topology is introduced in this paper as well. The main goal of this new design was to reach efficiency close to 99 \% by improving the performance of SAZZ topology through small modifications as discussed in the paper. The proposed modifications are simple, but result in substantial improvements with high conversion efficiency over 98 \% over whole practical region in the power range required by EV application.

   LCLC Resonant Converter as Maximum Power Point Tracker in PV Systems
By Alfonso CONESA, Guillermo VELASCO, Herminio MARTÃNEZ, Manuel ROMAN [View]
[Download]

Abstract: This paper presents the analysis and implementation of an LCLC resonant converter working as maximum power point tracker (MPPT) in a PV system. This converter must guarantee a constant DC output voltage and must vary its effective input resistance in order to extract the maximum power of the PV generator. Preliminary analysis concludes that not all resonant load topologies can achieve the design conditions for a MPPT. Only the LCLC and LLC converter are suitable for this purpose.

   Soft-switching Inverter for Variable Frequency Induction Heating Using Magnetic Energy Recovery Switch (MERS)
By TAKANORI ISOBE, Yoshitsugu MIYAJI, Tadayuki KITAHARA, Kazuhiko FUKUTANI, Ryuichi SHIMADA [View]
[Download]

Abstract: Variable frequency induction heating has great potential for industrial heating applications due to the possibility of heating distribution control. Conventional high frequency converters are not suitable for the variable frequency operation; therefore, large scale induction heating with variable frequency has not yet been introduced to practical use. This paper proposes a soft-switching converter using a concept of a magnetic energy recovery switch. Operation principles and characteristics are investigated and compared with other existing high frequency inverters. The proposed converter can be characterized by current source topology and wide frequency operating range with soft-switching. From discussions, the proposed converter is found to be suitable for high power variable frequency induction heating. The proposed converter has the challenge that semi-conductor switches must handle all of the load current and required load voltage to achieve wide frequency operation range, although conventional topologies utilize resonance capacitor to reduce semi-conductor ratings. This paper also describes current rating reduction by using shunt capacitor for the proposed converter. A simplified configuration to achieve the same concept is also proposed.

EPE 2009 - Subtopic 04-4 - DS: 'Soft Switch Converters'
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2009 - Conference > EPE 2009 - Topic 04: 'Soft Switch Converters' > EPE 2009 - Subtopic 04-4 - DS: 'Soft Switch Converters'
	[return to parent folder]

	A High Frequency Planar Transformer-linked ZVS DCâ€“DC Converter with Secondary-side Phase-Shifting PWM Rectifier By Tomokazu MISHIMA, Yuji YOSHIZAKO, Mutsuo NAKAOKA	[View] [Download]
Abstract: This paper presents a feasibility study of a zero voltage switching (ZVS) PWM full bridge (FB) DC-DC converter with high-frequency planar transformer-link. The soft-switching PWM FB DC-DC converter newly-developed for a switching power amplifier in a plasma generator can achieve soft commutations in switching power devices under the wide range of load power. Moreover, it can attain the effective reduction of idling power due to the phase-shift PWM scheme. In this paper, the essential experimental data obtained from a 100kHz -8kW prototype is described to demonstrate the practical effectiveness of the ZVS-PWM FB DC-DC converter.

	A High-Voltage Parallel Resonant Converter with single capacitor as an output filter By Juan DIAZ, Juan A. MARTIN-RAMOS, Alberto MARTIN-PERNIA, Juan A. MARTINEZ, Pedro J. VILLEGAS	[View] [Download]
Abstract: High-voltage converters have to keep large distances between primary and secondary, and also they use a large number of turns at the secondary side. For these reasons, an HV transformer usually has parastic elements that can not be neglected. The topologies have to cope with this extra components and it is desirable to include them in the topology. In fact, the serial resonant converter includes the leakage inductance, as well as the Parallel Resonant Converter, the PRC. This one includes also the parallel capacitor. In this paper, the PRC steady state modelling and experimental results are presented.

	A Motor-Friendly and Efficient Resonant DC-Link Converter By Calin PURCAREA, Jayalakshmi KEDARISETTI, Peter MUTSCHLER	[View] [Download]
Abstract: Parasitic high frequency (HF) phenomena for adjustable speed drives (ASD) fed by inverters with fast switching semiconductors are well known in literature. Although many advantages rise when using higher switching frequencies, like lower motor harmonics and audible noise, feeding the electrical machine through long cables lead to high voltage overshoots at motor terminals due to cable-motor impedance mismatch. Another important aspect in power converter design represents the efficiency, which has to be as high as possible. In this paper two topologies of resonant DC-link converter proving in the same time high efficient and motor-friendly are analyzed. Principle of operation are discussed together with control strategy and design. Motor-friendly characteristics are presented. Finally, simulations and measurements back up the reliability of chosen topology.

	A Push-Pull Converter Based Bidirectional DC-DC Interface for Energy Storage Systems By Eiji HIRAKI, Kazumasa HIRAO, Toshihiko TANAKA, Mishima TOMOKAZU	[View] [Download]
Abstract: In recent years, power electronic energy storage systems using super capacitor bank have been widely studied and developed for the electronic vehicles. In this paper, a full-bridge/centertapped push-pull circuit with active clamp-based soft switching bidirectional DC-DC converter and its control method are presented and discussed. From the results of basic experimental demonstration, the proposed system is able to perform adequate charging and discharging operation between low-voltage high-current super capacitor side and high-voltage low-current side with drive train and main battery. In addition, RCDi snubber losses appeared in the basic circuit topology are drastically reduced by ZCS/ZVS operation with the assistance of newly added active clump circuit, as well as ZVS operation with lossless snubber capacitor in high-voltage primary side.

	A Zero-Current-Switch Quasi-Resonant Boost Converter with Transformer Compensated Clamp Circuit By Eka FIRMANSYAH, Satoshi TOMIOKA, Seiya ABE, Masahito SHOYAMA, Tamotsu NINOMIYA	[View] [Download]
Abstract: This paper presents a method to prevent voltage ringing on the main switch of a full-wave zero-current-switch quasi-resonant (ZCS-QR) boost converter during its turn-off period. The proposed method does not incorporate any dissipative snubber in order to maintain efficiency of the converter. Severe clamp diode reverse recovery current and non-zero turn-on current occurred on the former diode-clamped ZCS-QR boost topology could be solved by this proposed topology without additional active switch and extra control effort. A detailed working principles and governing equations are explained. Experimental results showing the performance of the proposed converter are also included.

	Alternating Switching of Inductive Decoupled IGBTs in Voltage Source Inverters By Hans-GÃ¼nter ECKEL, Eberhard KRAFFT	[View] [Download]
Abstract: A new switching scheme for ZVS of inductive decoupled high voltage IGBTs is proposed. Each half bridge, consisting of two IGBT and two diodes, is split into two parallel half-bridges. The outputs of these half-bridges are decoupled by an inductance. An alternating switching scheme leads to hard switching turn-off and zero voltage switching turn-on. The IGBT turn-on losses can be reduced to less than 10\% compared to hard-switching. The reverse recovery stress for the free-wheeling diode determines the size of the decoupÂ¬ling inductor. As the IGBT turn-on and diode reverse-recovery losses are dominating at high voltage IGBT, the output current of the inverter can be significantly increased. In the paper, the different switching schemes for inductive decoupled inverter legs are compared. For the alternating switches scheme, the effect of the diode reverse recovery and the current redistribution during the conduction phases are explained in detail. Experimental results are given for 6.5 kV IGBT, the dependence of the diode reverse recovery stress on different operation parameters is discussed.

	Calorimetric Loss Measurements and Optimisation of High Power Resonant Converters for Pulsed Applications By Fabio CARASTRO	[View] [Download]
Abstract: This paper considers the calorimetric measurements of losses and the optimisation of high power resonant converters. For the tests a single phase resonant converter rated at 1 kV, 250 A (250 kW peak power, duty ratio 10 \%, 25 kW average power, pulse length 1ms) has been developed. This represents one phase of a multi-phase resonant power supply designed for long-pulse modulation (typically 1 ms to 2 ms) of RF tubes when equipped with a suitable output transformer. Pulsed operation is obtained by direct modulation of the high frequency power supply. The main aim of the work reported here is to calorimetrically monitor semiconductor losses and to experimentally optimise the value of turn-off snubber capacitors across the devices. The paper provides an overview of the technology and design used on the test rig prototype under study. Experimental results and semiconductor losses obtained through calorimetry will be provided to validate the effectiveness of the proposed techniques.

	Comparison of Non-Resonant and Super-Resonant Dual-Active ZVS-Operated High-Power DC/DC Converters By Robert LENKE, Florian MURA, Rik W. DE DONCKER	[View] [Download]
Abstract: Two bi-directional high-power dc-dc converter topologies with zero-voltage-switching (ZVS) operation over a defined load range are compared. These are the non-resonant dual-active bridge (DAB) and the dual-active series-resonant converter (DSRC) in super-resonant mode. A unified mathematical model describing both converters is presented, which treats the DAB as a boundary case of the super-resonant DSRC with infinite capacitance. It bases on a modification of an existing analytical analysis of the DSRC. Using the model, a method is developed to optimize the ac link transformer size for a limited dynamic voltage operating range with constant power capability, suitable for high-power converters in utility applications. The influence of the resonant capacitor on transformer size and other vital converter characteristics is quantitatively evaluated.

	IMPROVED CIRCUIT OF THE SWITCHED COUPLED-INDUCTOR CELL FOR DC-DC CONVERTERS WITH VERY LARGE CONVERSION RATIO By Boris AXELROD, Yefim BERKOVICH, Saad TAPUCHI, Adrian IOINOVICI	[View] [Download]
Abstract: By replacing the inductor in a basic boost converter by a multiple-coupled-inductor, and adding two diodes and a capacitor, a new converter with a large conversion ratio and low stresses on the switches is obtained. The additional diode helps to circulate the leakage inductance energy to the load in a non-oscillatory manner. The transistor turns on/off with soft-switching. The diodes turn on with zero-voltage switching and turn off with zero-current-switching, their reverse-recovery problem is alleviated. The voltage stress on both the transistor and diodes is less than the output voltage. Computer simulation and experimental results confirmed the theoretical expectations.

	Improvement for Very High Efficiency Chopper Circuit SAZZ By Yukinori TSURUTA, Martin PAVLOVSKY, Atsuo KAWAMURA	[View] [Download]
Abstract: The paper describes a study aiming at reaching a very high 99 \% efficiency in DC-DC chopper for electric vehicle (EV) application by improvements of conventional SAZZ topology. Optimisation of the operating frequency and the use multiple parallel SiC diodes were the main improvements of SAZZ chopper that were studied. These led to obtaining the efficiency of 98.96 \% in an 8 kW experimental setup. New, 30 kW fully bi-directional DC-DC converter based on SAZZ topology is introduced in this paper as well. The main goal of this new design was to reach efficiency close to 99 \% by improving the performance of SAZZ topology through small modifications as discussed in the paper. The proposed modifications are simple, but result in substantial improvements with high conversion efficiency over 98 \% over whole practical region in the power range required by EV application.

	LCLC Resonant Converter as Maximum Power Point Tracker in PV Systems By Alfonso CONESA, Guillermo VELASCO, Herminio MARTÃNEZ, Manuel ROMAN	[View] [Download]
Abstract: This paper presents the analysis and implementation of an LCLC resonant converter working as maximum power point tracker (MPPT) in a PV system. This converter must guarantee a constant DC output voltage and must vary its effective input resistance in order to extract the maximum power of the PV generator. Preliminary analysis concludes that not all resonant load topologies can achieve the design conditions for a MPPT. Only the LCLC and LLC converter are suitable for this purpose.

	Soft-switching Inverter for Variable Frequency Induction Heating Using Magnetic Energy Recovery Switch (MERS) By TAKANORI ISOBE, Yoshitsugu MIYAJI, Tadayuki KITAHARA, Kazuhiko FUKUTANI, Ryuichi SHIMADA	[View] [Download]
Abstract: Variable frequency induction heating has great potential for industrial heating applications due to the possibility of heating distribution control. Conventional high frequency converters are not suitable for the variable frequency operation; therefore, large scale induction heating with variable frequency has not yet been introduced to practical use. This paper proposes a soft-switching converter using a concept of a magnetic energy recovery switch. Operation principles and characteristics are investigated and compared with other existing high frequency inverters. The proposed converter can be characterized by current source topology and wide frequency operating range with soft-switching. From discussions, the proposed converter is found to be suitable for high power variable frequency induction heating. The proposed converter has the challenge that semi-conductor switches must handle all of the load current and required load voltage to achieve wide frequency operation range, although conventional topologies utilize resonance capacitor to reduce semi-conductor ratings. This paper also describes current rating reduction by using shunt capacitor for the proposed converter. A simplified configuration to achieve the same concept is also proposed.