EPE Association: EPE 2019 - DS1c: Hard & Soft Switching Techniques

EPE 2019 - DS1c: Hard & Soft Switching Techniques
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2019 ECCE Europe - Conference > EPE 2019 - Topic 02: Power Converter Topologies and Design > EPE 2019 - DS1c: Hard & Soft Switching Techniques

   [return to parent folder]

   A 10-MHz isolated Class DE resonant DC/DC converter based on GaN HEMT
By Junping HE [View]
[Download]

Abstract: The power density of DC/DC converter could be extremely increased when the switching frequency increases to the very high frequency (VHF, 30-300MHz generally). In addition, the soft-switching characteristic of power switches could contribute to the improvement of converter's efficiency. Therefore, VHF power converters with soft-switching characteristic have the merits of high power density and high efficiency, which keep in with the developmental tendency of advanced power electronic applications. In this paper, a 10-MHz 5W isolated resonant DC/DC converter based on GaN HEMT is designed and validated. The power stage of this 20Vin/5Vout converter consists of a Class DE inverter, a Class E rectifier and an air-core transformer. The output voltage of DC/DC converter is regulated by ON/OFF control. The zero-voltage switching (ZVS) operating principle and design procedures are amply introduced. The results obtained from simulation and experiment prototypes illustrate that ZVS characteristic of GaN HEMT can be achieved. In addition, air-core transformer and ON/OFF control are feasible functionally.

   A comparison between real-time harmonic elimination procedures for single phase CHB five level inverter
By Carlo CECATI [View]
[Download]

Abstract: Abstract--- In this paper, single phase cascaded H-bridge (CHB) 5-level inverters are considered and a pulse amplitude modulation (PAM) procedure operating at fundamental frequency, ables to remove the third and fifth harmonics and their respective multiple, is proposed. Each H-bridge is fed by equal voltage sources linearly dependent on modulation index. This procedure is compared with another PAM procedure that uses disequal dc voltage sources and with the classical selective harmonic elimination (SHE) technique working at fundamental frequency. The presented procedure eliminates more harmonics, therefore it returns lower Total Harmonic Distortion (THD) in comparison to the other considered strategies. Experimental results are shown, confirming the validity of the proposed procedure.

   Analysis and Design Methodology for ZVS Phase Shift Modulated Bidirectional CLLLC Resonant dc-dc Converters
By Weijian HAN [View]
[Download]

Abstract: The performance of classical frequency modulated bidirectional CLLLC resonant converter is heavilyaffected by the body diode reverse recovery and junction capacitance of the output rectifier. In thispaper, steady-state analysis and ZVS design methodology for a phase shift modulated ZVS CLLLCresonant converter is presented. In the proposed design, all the power switches are modulated with a fixed switching rate located the below series resonant frequency. A step-by-step design is formulated based on steady-state analysis, which maintains ZVS operation over a wide voltage range, and reduces conduction losses as much as possible. Compared with frequency modulation, phase shift modulation based on the proposed design yields less sensitivity with respect to switch parasitic parameters. Particularly, improved steady-state performance and enhanced efficiency can be achieved when MOSFETs with poor reverse recovery characteristics and/or large junction capacitance are employed. The analysis and proposed design is experimentally verified on a 800W half-bridge prototype.

   Experimental Characterization of the Passive Soft-Switching Snubber Inverter in SiC Motor Drive Applications
By Francesco PULSINELLI [View]
[Download]

Abstract: A deep analysis on the current overshoot and the overvoltage issues when high-dynamic power devices are used in motor drive applications is discussed in this paper. The influence of the power cable and of the electrical motor at the commutation events of the power semiconductors is verified through a double pulse test setup. To overcome the problem of the overvoltage at the motor side, the design and implementation of the Passive Soft-Switching Snubber Inverter for motor drive applications are presented. The proposed topology is analyzed and tested through the simulations and the experimental campaign. The results show that this topology allows to reduce the overvoltage at the motor terminals when fast commutations and long power cables are used.

   H-Bridge Converter as Power Electronics Workbench: An Effective Teaching Case of Learning by Doing
By Salvatore MUSUMECI [View]
[Download]

Abstract: This paper deals with a 'learn by doing' approach applied to teach power electronics. A full-Bridge converter is used as a workbench for the laboratory activities of the power electronics class. In the proposed paper, the H-Bridge is the fundamental building block to explain the most important power electronics topics in several operative conditions and with different topologies. An H-Bridge with an LCL load is considered, to realize, rearranging the topology, basic DC-DC converter solutions such as Buck, Boost and Buck-Boost. A user-friendly software and hardware set-up is realized to investigate both switching performances and control technique of several converter topologies. The proposed experimental teaching system allows an effective method to acquire the most important power electronics notions through a learn by doing method.

   Novel Analysis and Optimal Modulation Scheme of Reactive Power Isolated Dual Active Bridge DC/DC Converter
By SHIEN WANG [View]
[Download]

Abstract: This paper first classifies reactive current in isolated dual-active-bridge (DAB) dc-dc converter into different categories and analysis their influences. Differs from previous frequency domain model, this letter presents a unified time domain definition of the active component and the reactive component of HFL current and HFL power. Then, specific expression of reactive current and reactive power is derived for all voltage patterns of DAB. On this basis, the minimum reactive power phase shift modulation scheme is proposed to reduce the reactive power on both bridges. At last, the effectiveness of the proposed analysis and modulation scheme were validated with a laboratory prototype.

   Operation Analysis and Implementation of a GaN Based Bidirectional CLLC Converter with Synchronous Rectification
By Thorben SCHOBRE [View]
[Download]

Abstract: In this paper a 3.6 kW GaN based bidirectional CLLC converter is investigated. The switching statesequences are analyzed for operating below and above the series resonant frequency. Based on the fundamental harmonic approximation the resonant tank of the CLLC converter is designed. To increase the efficiency a synchronous rectification is proposed and implemented. The transfer behavior is measured in the prototype and compared to the FHA. The efficiency is measured under full load condition.

   Parameter Design of Isolated AC/DC Converter for Using Soft-Switching Technique
By Naoki HIROSE [View]
[Download]

Abstract: This paper presents the parameter design of unidirectional isolated AC/DC converter for using soft-switching technique. The authors propose the circuit configuration and parameter design in order to satisfy soft-switching condition. The effectiveness of the parameter design of isolated AC/DC converter is verified by experiments.

   Quasi Variable Capacitor for Efficient Heating by Induction Heating
By Sachio KUBOTA [View]
[Download]

Abstract: This paper presents some quasi variable capacitors applied for resonance tracking control.In order to maintain a soft switching, it is necessary to track a resonance. Although PFM (Pulse Frequency Modulation) is usually utilized as a resonance tracking control, there is a problem in the case of IH. The heating part is not changed since a resonance is tracked at constant frequency by quasi variable capacitor. Moreover, quasi variable capacitor can be widely used for various conventional inverters such as SEPP (Single Ended Push Pull) inverter, Half bridge inverter and Full bridge inverter. In this paper, validity of the proposed quasi variable capacitor is verified from the simulated results and experimental results.

   Suppressing Leakage Current for Cascaded H-bridge Converters in Grid-Tie Renewable Energy Systems
By Izgun GUNSAL [View]
[Download]

Abstract: Photovoltaic panels contain parasitic capacitance causing leakage currents in transformerless converters, which raises safety concerns and reduces system performance. This work presents a common-mode equivalent circuit for Cascaded H-Bridge (CHB) converters with symmetrical filter configuration. In this paper, we develop a novel modulation technique for CHB multilevel converter, which can suppress the leakage current. The simulation and experimental results for standard phase shifted pulse width modulation and novel leakage reduction pulse width modulation (LRPWM) are provided. It is found that LRPWM is more effective in suppressing leakage current.

EPE 2019 - DS1c: Hard & Soft Switching Techniques
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2019 ECCE Europe - Conference > EPE 2019 - Topic 02: Power Converter Topologies and Design > EPE 2019 - DS1c: Hard & Soft Switching Techniques
	[return to parent folder]

	A 10-MHz isolated Class DE resonant DC/DC converter based on GaN HEMT By Junping HE	[View] [Download]
Abstract: The power density of DC/DC converter could be extremely increased when the switching frequency increases to the very high frequency (VHF, 30-300MHz generally). In addition, the soft-switching characteristic of power switches could contribute to the improvement of converter's efficiency. Therefore, VHF power converters with soft-switching characteristic have the merits of high power density and high efficiency, which keep in with the developmental tendency of advanced power electronic applications. In this paper, a 10-MHz 5W isolated resonant DC/DC converter based on GaN HEMT is designed and validated. The power stage of this 20Vin/5Vout converter consists of a Class DE inverter, a Class E rectifier and an air-core transformer. The output voltage of DC/DC converter is regulated by ON/OFF control. The zero-voltage switching (ZVS) operating principle and design procedures are amply introduced. The results obtained from simulation and experiment prototypes illustrate that ZVS characteristic of GaN HEMT can be achieved. In addition, air-core transformer and ON/OFF control are feasible functionally.

	A comparison between real-time harmonic elimination procedures for single phase CHB five level inverter By Carlo CECATI	[View] [Download]
Abstract: Abstract--- In this paper, single phase cascaded H-bridge (CHB) 5-level inverters are considered and a pulse amplitude modulation (PAM) procedure operating at fundamental frequency, ables to remove the third and fifth harmonics and their respective multiple, is proposed. Each H-bridge is fed by equal voltage sources linearly dependent on modulation index. This procedure is compared with another PAM procedure that uses disequal dc voltage sources and with the classical selective harmonic elimination (SHE) technique working at fundamental frequency. The presented procedure eliminates more harmonics, therefore it returns lower Total Harmonic Distortion (THD) in comparison to the other considered strategies. Experimental results are shown, confirming the validity of the proposed procedure.

	Analysis and Design Methodology for ZVS Phase Shift Modulated Bidirectional CLLLC Resonant dc-dc Converters By Weijian HAN	[View] [Download]
Abstract: The performance of classical frequency modulated bidirectional CLLLC resonant converter is heavilyaffected by the body diode reverse recovery and junction capacitance of the output rectifier. In thispaper, steady-state analysis and ZVS design methodology for a phase shift modulated ZVS CLLLCresonant converter is presented. In the proposed design, all the power switches are modulated with a fixed switching rate located the below series resonant frequency. A step-by-step design is formulated based on steady-state analysis, which maintains ZVS operation over a wide voltage range, and reduces conduction losses as much as possible. Compared with frequency modulation, phase shift modulation based on the proposed design yields less sensitivity with respect to switch parasitic parameters. Particularly, improved steady-state performance and enhanced efficiency can be achieved when MOSFETs with poor reverse recovery characteristics and/or large junction capacitance are employed. The analysis and proposed design is experimentally verified on a 800W half-bridge prototype.

	Experimental Characterization of the Passive Soft-Switching Snubber Inverter in SiC Motor Drive Applications By Francesco PULSINELLI	[View] [Download]
Abstract: A deep analysis on the current overshoot and the overvoltage issues when high-dynamic power devices are used in motor drive applications is discussed in this paper. The influence of the power cable and of the electrical motor at the commutation events of the power semiconductors is verified through a double pulse test setup. To overcome the problem of the overvoltage at the motor side, the design and implementation of the Passive Soft-Switching Snubber Inverter for motor drive applications are presented. The proposed topology is analyzed and tested through the simulations and the experimental campaign. The results show that this topology allows to reduce the overvoltage at the motor terminals when fast commutations and long power cables are used.

	H-Bridge Converter as Power Electronics Workbench: An Effective Teaching Case of Learning by Doing By Salvatore MUSUMECI	[View] [Download]
Abstract: This paper deals with a 'learn by doing' approach applied to teach power electronics. A full-Bridge converter is used as a workbench for the laboratory activities of the power electronics class. In the proposed paper, the H-Bridge is the fundamental building block to explain the most important power electronics topics in several operative conditions and with different topologies. An H-Bridge with an LCL load is considered, to realize, rearranging the topology, basic DC-DC converter solutions such as Buck, Boost and Buck-Boost. A user-friendly software and hardware set-up is realized to investigate both switching performances and control technique of several converter topologies. The proposed experimental teaching system allows an effective method to acquire the most important power electronics notions through a learn by doing method.

	Novel Analysis and Optimal Modulation Scheme of Reactive Power Isolated Dual Active Bridge DC/DC Converter By SHIEN WANG	[View] [Download]
Abstract: This paper first classifies reactive current in isolated dual-active-bridge (DAB) dc-dc converter into different categories and analysis their influences. Differs from previous frequency domain model, this letter presents a unified time domain definition of the active component and the reactive component of HFL current and HFL power. Then, specific expression of reactive current and reactive power is derived for all voltage patterns of DAB. On this basis, the minimum reactive power phase shift modulation scheme is proposed to reduce the reactive power on both bridges. At last, the effectiveness of the proposed analysis and modulation scheme were validated with a laboratory prototype.

	Operation Analysis and Implementation of a GaN Based Bidirectional CLLC Converter with Synchronous Rectification By Thorben SCHOBRE	[View] [Download]
Abstract: In this paper a 3.6 kW GaN based bidirectional CLLC converter is investigated. The switching statesequences are analyzed for operating below and above the series resonant frequency. Based on the fundamental harmonic approximation the resonant tank of the CLLC converter is designed. To increase the efficiency a synchronous rectification is proposed and implemented. The transfer behavior is measured in the prototype and compared to the FHA. The efficiency is measured under full load condition.

	Parameter Design of Isolated AC/DC Converter for Using Soft-Switching Technique By Naoki HIROSE	[View] [Download]
Abstract: This paper presents the parameter design of unidirectional isolated AC/DC converter for using soft-switching technique. The authors propose the circuit configuration and parameter design in order to satisfy soft-switching condition. The effectiveness of the parameter design of isolated AC/DC converter is verified by experiments.

	Quasi Variable Capacitor for Efficient Heating by Induction Heating By Sachio KUBOTA	[View] [Download]
Abstract: This paper presents some quasi variable capacitors applied for resonance tracking control.In order to maintain a soft switching, it is necessary to track a resonance. Although PFM (Pulse Frequency Modulation) is usually utilized as a resonance tracking control, there is a problem in the case of IH. The heating part is not changed since a resonance is tracked at constant frequency by quasi variable capacitor. Moreover, quasi variable capacitor can be widely used for various conventional inverters such as SEPP (Single Ended Push Pull) inverter, Half bridge inverter and Full bridge inverter. In this paper, validity of the proposed quasi variable capacitor is verified from the simulated results and experimental results.

	Suppressing Leakage Current for Cascaded H-bridge Converters in Grid-Tie Renewable Energy Systems By Izgun GUNSAL	[View] [Download]
Abstract: Photovoltaic panels contain parasitic capacitance causing leakage currents in transformerless converters, which raises safety concerns and reduces system performance. This work presents a common-mode equivalent circuit for Cascaded H-Bridge (CHB) converters with symmetrical filter configuration. In this paper, we develop a novel modulation technique for CHB multilevel converter, which can suppress the leakage current. The simulation and experimental results for standard phase shifted pulse width modulation and novel leakage reduction pulse width modulation (LRPWM) are provided. It is found that LRPWM is more effective in suppressing leakage current.