EPE Association: EPE 2011 - DS3c: Topic 04: Soft Switching Converters and Control

EPE 2011 - DS3c: Topic 04: Soft Switching Converters and Control
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2011 ECCE Europe - Conference > EPE 2011 - Topic 04: Soft Switching Converters and Control > EPE 2011 - DS3c: Topic 04: Soft Switching Converters and Control

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   A Current Fed Multi-resonant Converter with Extended Voltage Regulation Range
By Donghao LI, Bo LIU, Bo YUAN, Xu YANG, Qingyi HUANG, Jerry ZHAI [View]
[Download]

Abstract: A previously proposed current fed multi-resonant converter (CFMRC) has the merits of low input current ripple, high step-up capability and high efficiency. However, in order to ensure zero-current switching (ZCS) of its secondary rectifying diodes, the switching frequency range is limited hence the voltage regulation range is limited. In this paper, the switching frequency range is broadened for the purpose of extending the voltage regulation range of the CFMRC. Although ZCS of the rectifying diodes are lost when pushing the switching frequency much higher than the resonant frequency, SiC diodes are applied to the secondary rectifier to eliminate the reverse recovery issue and the efficiency of the converter is not affected much. The merits of the proposed converter is verified by a 150 W prototype operating from 255 kHz to 355 kHz, the voltage gain achieves 22 at 355 kHz switching frequency and the peak efficiency is as high as 96\%.

   A Design Methodology of Resonant LLC DC-DC Converter
By Alexander ABRAMOVITZ, Svetlana BRONSHTEIN [View]
[Download]

Abstract: This paper suggests a design procedure of LLC resonant converter with capacitive filter based on an equivalent ac resistance model of the rectifier valid for Discontinuous as well as Continuous Conduction Modes. The dc voltage conversion ratio plots are presented. The theory is verified by simulation and experiment

   A New High Step-Up Voltage Ratio Soft Switching PWM Boost DC–DC Power Converter with Edge Resonant Switched Capacitor Modular
By Tomokazu MISHIMA, Yujiro TAKEUCHI, Mutsuo NAKAOKA [View]
[Download]

Abstract: This paper presents a new soft switching PWM non-isolated boost DC-DC converter embedding an edge resonant switched capacitor (ER-SWC) modular. The soft switching PWM boost DC--DC converter treated here can achieve a high frequency zero current switching (ZCS) turn-on and zero voltage switching (ZVS) turn-off operations in active switches and minimize a reverse recovering current in the freewheeling diode under DCM including CRM conditions in the input inductor current. Those advantageous properties enable a wide range of soft switching operations together with a high step-up voltage conversion ratio due to the edge resonance in the ER-SWC modular, which results in the high efficiency power conversion. For demonstrating the effectiveness of the new soft switching PWM boost DC-DC converter, a 1 kW-40 kHz laboratory prototype is evaluated in experiments, followed by the design guideline of the DC-DC converter and a theoretical analysis. Then, the performances of the proposed soft switching PWM boost DC-DC converter are discussed from a practical point of view.

   A Soft Switching Class D Current Source Inverter for Induction Heating with Non-Ferromagnetic Load
By Samart YACHIANGKAM [View]
[Download]

Abstract: A class D current source resonant inverter (CSRI) with interleaved buck converter for induction heating power supplies for non-ferromagnetic load is proposed in this paper. The switching devices of CSRI are connected through the common ground and only a single dc power supply is needed for the gate driver circuitry. The maximum output power transferred to the load for the hardware prototype is 1.26 kW. The resonant inverter operates at a fixed frequency of 108 kHz while the interleaved buck converter operates at 40 kHz for soft-switching operation. The output power is controlled by adjusting the pulse width of the interleaved buck converter. The hardware prototype is capable for melting a 30-gram aluminum workpiece at 700 degree Celsius within 25 minutes.

   Comparison of Resonant LLC and LCC Converters for Low-Profile Applications
By Alexander PAWELLEK, Thomas DUERBAUM, Christian OEDER [View]
[Download]

Abstract: Due to the increasingly demand for highly efficient, cost-effective and low-profile applications, resonant converter topologies are massively gaining in importance. With the LCC and LLC converter, the two most promising topologies of this converter class are presented and compared within this paper. Based on their individual configuration, both converters are analyzed in the time domain revealing the first differences and similarities. Moreover, both converter topologies are optimized with respect to a low-profile notebook adapter specification for 100 W. The main focus is placed on the magnetic design of both transformers. Finally, two prototypes using completely identical layouts are developed and measurement results are discussed concerning best operation point and overall efficiency.

   Heating Method for Ferromagnetic Metal by Power Factor Control
By Sachio KUBOTA, Fumio ITO, Yoshihiro SHIOAMOKA, Naoki YAMAMOTO [View]
[Download]

Abstract: This paper presents a novel heating method for ferromagnetic metal and the power supply for induction heating. It is known that ferromagnetic metals are heated more easily than paramagnetic metals. However, when ferromagnetic metals are heated more than Curie temperature, their physical properties become the same as paramagnetic metals. In other words, a power supply may be destroyed because a soft switching cannot be maintained. Therefore the power supply and control method are newly proposed. This power supply always achieves a soft switching although metals are heated from low temperature to high temperature. In this power supply, not frequency control but power factor control is applied as new control method. A power factor is controlled with Pulse Width Modulation. It is realized with the simple circuit composition which is connecting one auxiliary switch and one capacitor to full bridge inverter.

   High-frequency Soft-switching Current-fed Inverter for Off-grid Micro-generation: Fuel Cell Application for Rural Electrification/Development
By Akshay RATHORE [View]
[Download]

Abstract: This paper presents a high-frequency (HF) zero-voltage switching (ZVS) current-fed three-phase inverter for fuel cell based off-grid micro-generation applications, preferably for rural electrification or rural development. Current-fed configuration at front-end draws nearly a dc current with a small ripple magnitude resulting in saving of fuel (hydrogen). It increases the fuel cells efficiency and therefore, the overall efficiency of the system. The full range soft-switching improves the part load efficiency and makes the system scalable for high-frequency high power applications.

   Medium frequency transformer in resonant switching dc/dc-converters for railway applications
By Holger HOFFMANN, Bernhard PIEPENBREIER [View]
[Download]

Abstract: A converter system based on medium frequency dc/dc-converters can replace the conventional tractiontransformer saving both mass and energy.A medium-frequency-transformer design-procedure is introduced that allows a clear representation oftransformers total mass and efficiency under consideration of thermal aspects. Measurements with aprototyped mf-transformer verify the calculated results.

   New resonant inverter topology with active energy recovery in PDM mode for DBD plasma reactor supply
By Tomasz JAKUBOWSKI, Stanislaw KALISIAK, Marcin HOLUB, Ryszard PALKA, Tadeusz BORKOWSKI, Jaroslaw MYSKOW [View]
[Download]

Abstract: Dielectric barrier discharge reactors are often operated using the pulse density modulation technique. A new resonant converter topology is proposed with energy recovery circuit for efficient PDM mode operation. System description, simulation results and test-stand waveforms are presented and discussed. System topology allows fluent peak-to-peak output voltage control in the resonant mode. Very high efficiency of over 90\% is obtained with the means of energy recovery subsystem. High voltage operation is presented with the pulse density modulation (PDM) technique in order to obtain controllable power dissipation into plasma. Exemplary application results regarding marine diesel engine exhaust cleaning are briefly discussed.

   Overview of Novel Loss-Mitigating Schemes for High-Frequency-Link Inverters with Application Potential for PV, Wind, Fuel Cell, Energy Storage, and EV/HEV
By Sudip MAZUMDER [View]
[Download]

Abstract: Recently, several new loss-mitigating modulation strategies have been developed for high-frequency-link (HFL) inverters, which demonstrate capability for high efficiency and low total harmonic distortion (THD) in spite of the fact that, the HFL inverter operates without any intermediate dc-link filter. An overview of these technologies and mechanisms and their performance evaluation have been provided in this paper. The compactness, direct power conversion (DPC), and dc-link-filter-less solution (hence high reliability) of the HFL inverters make them suitable candidates for renewable and alternative energy applications for smart grids and smart microgrids including photovoltaics, wind, fuel cell, energy storage as well as for battery-vehicle (e.g. EV/HEV/PHEV) applications.

   Parallel/Series Connection of Self-Sustained Oscillating Series-Parallel Resonant Converters
By Hubert AIGNER, Juergen BIELA [View]
[Download]

Abstract: In this paper, a new interconnection concept of two (or more) series-parallel resonant converter suitable for parallel/series connected inputs is proposed. With this connection method operationat a wide range of operating voltages and good semiconductor utilisation is enabled. Furthermore, the balance of the two resonant converter input voltages in case of a series connection is investigated and a method for improving the voltage balancing is presented. The proposed concept is verified by measurement results and the design of the converter/integrated transformer is discussed in detail.

   Resonant Inverter with a Variable-Frequency Asymmetrical Voltage-Cancellation Control for Low Q-Factor Loads in Induction Cooking
By Samart YACHIANGKAM [View]
[Download]

Abstract: This paper presents a power control strategy of the full-bridge series resonant inverter based on the asymmetrical voltage-cancellation control with variable-frequency in induction cooking appliances with a load of low Q factor on the domestic markets. The switching frequency of inverter is suitably operated higher than the resonant frequency under zero-voltage-switching (ZVS) condition. The proposed control strategy ensures to minimize the switching loss in all switches of inverter, so that can improve the efficiency of inverter system. The theoretical results of proposed control method are verified by simulation and experimental results as shown in this paper. The advantages of the proposed control are simple, low switching loss and system reliability for the entire operating region.

   Soft Switching Three Level Inverter with Passive Snubber Circuit (S3L Inverter)
By Manfred W. GEKELER [View]
[Download]

Abstract: Presented here is a three level voltage source inverter for electric drives, uninterruptable power supplies and for mains feeds. Unlike the usual hard switching topologies, it is implemented as completely soft switching. A novel patented snubber circuit is added, which is structured very simply and consists of only a few passive components. This snubber circuit works in principle without any losses; all switching operations in the three level voltage source inverter are in principle free of switching losses. For this reason, very high values of switching frequency up to about 40 kHz, and very high efficiencies up to more than 98\%, can be realized, even with utilization of economical standard IGBT's. In particular with utilization of IGCT's, an effective di/dt limitation is to be emphasized, which works without additional inductive voltage stressing of the IGCT's.

   Thermal-Electrical Modeling and Simulation of Resonantly Operated DC-DC Converters Based on Extended Describing Function Method
By Zhiyu CAO, Jianxun LV, Norbert FROEHLEKE, Joachim BOECKER, Haiwen YUAN [View]
[Download]

Abstract: Due to the very large difference between electrical and thermal time constants, stimulation forresonantly operated DC-DC converters using physical or ideal switching model is very time-consumingor impossible with limited computational resources. In order to overcome this problem a novelthermal-electrical averaging model of resonantly operated DC-DC converters is proposed in thiscontribution. The electrical model is based on extended describing function method. All requiredparameters for the thermal model can be obtained from datasheets. As examples thermal-electricalmodels of series-parallel resonant converters with LC- and C-type output filters are given and verifiedby comparison with a standard simulation tool. The thermal-electrical modeling procedure proposed inthis contribution can of course also be applied for other types of resonant converters.

EPE 2011 - DS3c: Topic 04: Soft Switching Converters and Control
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2011 ECCE Europe - Conference > EPE 2011 - Topic 04: Soft Switching Converters and Control > EPE 2011 - DS3c: Topic 04: Soft Switching Converters and Control
	[return to parent folder]

	A Current Fed Multi-resonant Converter with Extended Voltage Regulation Range By Donghao LI, Bo LIU, Bo YUAN, Xu YANG, Qingyi HUANG, Jerry ZHAI	[View] [Download]
Abstract: A previously proposed current fed multi-resonant converter (CFMRC) has the merits of low input current ripple, high step-up capability and high efficiency. However, in order to ensure zero-current switching (ZCS) of its secondary rectifying diodes, the switching frequency range is limited hence the voltage regulation range is limited. In this paper, the switching frequency range is broadened for the purpose of extending the voltage regulation range of the CFMRC. Although ZCS of the rectifying diodes are lost when pushing the switching frequency much higher than the resonant frequency, SiC diodes are applied to the secondary rectifier to eliminate the reverse recovery issue and the efficiency of the converter is not affected much. The merits of the proposed converter is verified by a 150 W prototype operating from 255 kHz to 355 kHz, the voltage gain achieves 22 at 355 kHz switching frequency and the peak efficiency is as high as 96\%.

	A Design Methodology of Resonant LLC DC-DC Converter By Alexander ABRAMOVITZ, Svetlana BRONSHTEIN	[View] [Download]
Abstract: This paper suggests a design procedure of LLC resonant converter with capacitive filter based on an equivalent ac resistance model of the rectifier valid for Discontinuous as well as Continuous Conduction Modes. The dc voltage conversion ratio plots are presented. The theory is verified by simulation and experiment

	A New High Step-Up Voltage Ratio Soft Switching PWM Boost DC–DC Power Converter with Edge Resonant Switched Capacitor Modular By Tomokazu MISHIMA, Yujiro TAKEUCHI, Mutsuo NAKAOKA	[View] [Download]
Abstract: This paper presents a new soft switching PWM non-isolated boost DC-DC converter embedding an edge resonant switched capacitor (ER-SWC) modular. The soft switching PWM boost DC--DC converter treated here can achieve a high frequency zero current switching (ZCS) turn-on and zero voltage switching (ZVS) turn-off operations in active switches and minimize a reverse recovering current in the freewheeling diode under DCM including CRM conditions in the input inductor current. Those advantageous properties enable a wide range of soft switching operations together with a high step-up voltage conversion ratio due to the edge resonance in the ER-SWC modular, which results in the high efficiency power conversion. For demonstrating the effectiveness of the new soft switching PWM boost DC-DC converter, a 1 kW-40 kHz laboratory prototype is evaluated in experiments, followed by the design guideline of the DC-DC converter and a theoretical analysis. Then, the performances of the proposed soft switching PWM boost DC-DC converter are discussed from a practical point of view.

	A Soft Switching Class D Current Source Inverter for Induction Heating with Non-Ferromagnetic Load By Samart YACHIANGKAM	[View] [Download]
Abstract: A class D current source resonant inverter (CSRI) with interleaved buck converter for induction heating power supplies for non-ferromagnetic load is proposed in this paper. The switching devices of CSRI are connected through the common ground and only a single dc power supply is needed for the gate driver circuitry. The maximum output power transferred to the load for the hardware prototype is 1.26 kW. The resonant inverter operates at a fixed frequency of 108 kHz while the interleaved buck converter operates at 40 kHz for soft-switching operation. The output power is controlled by adjusting the pulse width of the interleaved buck converter. The hardware prototype is capable for melting a 30-gram aluminum workpiece at 700 degree Celsius within 25 minutes.

	Comparison of Resonant LLC and LCC Converters for Low-Profile Applications By Alexander PAWELLEK, Thomas DUERBAUM, Christian OEDER	[View] [Download]
Abstract: Due to the increasingly demand for highly efficient, cost-effective and low-profile applications, resonant converter topologies are massively gaining in importance. With the LCC and LLC converter, the two most promising topologies of this converter class are presented and compared within this paper. Based on their individual configuration, both converters are analyzed in the time domain revealing the first differences and similarities. Moreover, both converter topologies are optimized with respect to a low-profile notebook adapter specification for 100 W. The main focus is placed on the magnetic design of both transformers. Finally, two prototypes using completely identical layouts are developed and measurement results are discussed concerning best operation point and overall efficiency.

	Heating Method for Ferromagnetic Metal by Power Factor Control By Sachio KUBOTA, Fumio ITO, Yoshihiro SHIOAMOKA, Naoki YAMAMOTO	[View] [Download]
Abstract: This paper presents a novel heating method for ferromagnetic metal and the power supply for induction heating. It is known that ferromagnetic metals are heated more easily than paramagnetic metals. However, when ferromagnetic metals are heated more than Curie temperature, their physical properties become the same as paramagnetic metals. In other words, a power supply may be destroyed because a soft switching cannot be maintained. Therefore the power supply and control method are newly proposed. This power supply always achieves a soft switching although metals are heated from low temperature to high temperature. In this power supply, not frequency control but power factor control is applied as new control method. A power factor is controlled with Pulse Width Modulation. It is realized with the simple circuit composition which is connecting one auxiliary switch and one capacitor to full bridge inverter.

	High-frequency Soft-switching Current-fed Inverter for Off-grid Micro-generation: Fuel Cell Application for Rural Electrification/Development By Akshay RATHORE	[View] [Download]
Abstract: This paper presents a high-frequency (HF) zero-voltage switching (ZVS) current-fed three-phase inverter for fuel cell based off-grid micro-generation applications, preferably for rural electrification or rural development. Current-fed configuration at front-end draws nearly a dc current with a small ripple magnitude resulting in saving of fuel (hydrogen). It increases the fuel cells efficiency and therefore, the overall efficiency of the system. The full range soft-switching improves the part load efficiency and makes the system scalable for high-frequency high power applications.

	Medium frequency transformer in resonant switching dc/dc-converters for railway applications By Holger HOFFMANN, Bernhard PIEPENBREIER	[View] [Download]
Abstract: A converter system based on medium frequency dc/dc-converters can replace the conventional tractiontransformer saving both mass and energy.A medium-frequency-transformer design-procedure is introduced that allows a clear representation oftransformers total mass and efficiency under consideration of thermal aspects. Measurements with aprototyped mf-transformer verify the calculated results.

	New resonant inverter topology with active energy recovery in PDM mode for DBD plasma reactor supply By Tomasz JAKUBOWSKI, Stanislaw KALISIAK, Marcin HOLUB, Ryszard PALKA, Tadeusz BORKOWSKI, Jaroslaw MYSKOW	[View] [Download]
Abstract: Dielectric barrier discharge reactors are often operated using the pulse density modulation technique. A new resonant converter topology is proposed with energy recovery circuit for efficient PDM mode operation. System description, simulation results and test-stand waveforms are presented and discussed. System topology allows fluent peak-to-peak output voltage control in the resonant mode. Very high efficiency of over 90\% is obtained with the means of energy recovery subsystem. High voltage operation is presented with the pulse density modulation (PDM) technique in order to obtain controllable power dissipation into plasma. Exemplary application results regarding marine diesel engine exhaust cleaning are briefly discussed.

	Overview of Novel Loss-Mitigating Schemes for High-Frequency-Link Inverters with Application Potential for PV, Wind, Fuel Cell, Energy Storage, and EV/HEV By Sudip MAZUMDER	[View] [Download]
Abstract: Recently, several new loss-mitigating modulation strategies have been developed for high-frequency-link (HFL) inverters, which demonstrate capability for high efficiency and low total harmonic distortion (THD) in spite of the fact that, the HFL inverter operates without any intermediate dc-link filter. An overview of these technologies and mechanisms and their performance evaluation have been provided in this paper. The compactness, direct power conversion (DPC), and dc-link-filter-less solution (hence high reliability) of the HFL inverters make them suitable candidates for renewable and alternative energy applications for smart grids and smart microgrids including photovoltaics, wind, fuel cell, energy storage as well as for battery-vehicle (e.g. EV/HEV/PHEV) applications.

	Parallel/Series Connection of Self-Sustained Oscillating Series-Parallel Resonant Converters By Hubert AIGNER, Juergen BIELA	[View] [Download]
Abstract: In this paper, a new interconnection concept of two (or more) series-parallel resonant converter suitable for parallel/series connected inputs is proposed. With this connection method operationat a wide range of operating voltages and good semiconductor utilisation is enabled. Furthermore, the balance of the two resonant converter input voltages in case of a series connection is investigated and a method for improving the voltage balancing is presented. The proposed concept is verified by measurement results and the design of the converter/integrated transformer is discussed in detail.

	Resonant Inverter with a Variable-Frequency Asymmetrical Voltage-Cancellation Control for Low Q-Factor Loads in Induction Cooking By Samart YACHIANGKAM	[View] [Download]
Abstract: This paper presents a power control strategy of the full-bridge series resonant inverter based on the asymmetrical voltage-cancellation control with variable-frequency in induction cooking appliances with a load of low Q factor on the domestic markets. The switching frequency of inverter is suitably operated higher than the resonant frequency under zero-voltage-switching (ZVS) condition. The proposed control strategy ensures to minimize the switching loss in all switches of inverter, so that can improve the efficiency of inverter system. The theoretical results of proposed control method are verified by simulation and experimental results as shown in this paper. The advantages of the proposed control are simple, low switching loss and system reliability for the entire operating region.

	Soft Switching Three Level Inverter with Passive Snubber Circuit (S3L Inverter) By Manfred W. GEKELER	[View] [Download]
Abstract: Presented here is a three level voltage source inverter for electric drives, uninterruptable power supplies and for mains feeds. Unlike the usual hard switching topologies, it is implemented as completely soft switching. A novel patented snubber circuit is added, which is structured very simply and consists of only a few passive components. This snubber circuit works in principle without any losses; all switching operations in the three level voltage source inverter are in principle free of switching losses. For this reason, very high values of switching frequency up to about 40 kHz, and very high efficiencies up to more than 98\%, can be realized, even with utilization of economical standard IGBT's. In particular with utilization of IGCT's, an effective di/dt limitation is to be emphasized, which works without additional inductive voltage stressing of the IGCT's.

	Thermal-Electrical Modeling and Simulation of Resonantly Operated DC-DC Converters Based on Extended Describing Function Method By Zhiyu CAO, Jianxun LV, Norbert FROEHLEKE, Joachim BOECKER, Haiwen YUAN	[View] [Download]
Abstract: Due to the very large difference between electrical and thermal time constants, stimulation forresonantly operated DC-DC converters using physical or ideal switching model is very time-consumingor impossible with limited computational resources. In order to overcome this problem a novelthermal-electrical averaging model of resonantly operated DC-DC converters is proposed in thiscontribution. The electrical model is based on extended describing function method. All requiredparameters for the thermal model can be obtained from datasheets. As examples thermal-electricalmodels of series-parallel resonant converters with LC- and C-type output filters are given and verifiedby comparison with a standard simulation tool. The thermal-electrical modeling procedure proposed inthis contribution can of course also be applied for other types of resonant converters.