EPE Association: EPE 2001 - Topic 02a: Soft Switching Converters (Resonant, ZVS, ZCS)

EPE 2001 - Topic 02a: Soft Switching Converters (Resonant, ZVS, ZCS)
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2001 - Conference > EPE 2001 - Topic 02: POWER ELECTRONICS CONVERTER CIRCUITS > EPE 2001 - Topic 02a: Soft Switching Converters (Resonant, ZVS, ZCS)

   [return to parent folder]

   A Comparison Of LCC Inverters With Resonant Current Control As A HPS..
By F. Rodríguez; J. Ribas; J. Cardesín; J. M. Alonso; E. L. Corominas; A. Calleja; J. García; M. Rico-Secades [View]
[Download]

Abstract: The goal of this paper is to compare the LCC-Series Parallel Resonant Inverter with the LCC-Parallel Series Resonant Inverter, both working with the same control method (Resonant Current Control). This control forces the inverter to operate with optimum commutations and without handling any reactive energy, thus minimising both switching and conduction losses. Also, a graphic design method to calculate the resonant tank elements for both, the SP and the PS topologies is shown. This method is based on the Output–power vs Load–resistance Optimum Commutations curves.

   A High PFC Doubler Half Bridge Boost without Losses of Commutation
By R. M. Finzi Neto; J. B. Vieira Jr.; L.H.B.S.C Barreto; E.A. Coelho; Luiz C. Freitas [View]
[Download]

Abstract: This paper presents a High Power Factor Doubler Half Bridge Boost Converter without losses of commutation to obtain high output voltages with a simple control. A detailed analysis of its functioning is presented. Simulation results of the proposed topology are presented to confirm the proposed ideas. In order to corroborate this approach, mathematical analysis and experimental results are presented.

   An Optimal Lossless Commutation PWM Two Level Forward Converter ...
By R. M. Finzi Neto; J. B. Vieira Jr.; E.A. Coelho; L.H.B.S.C Barreto; V.J. Farias; L. C. Freitas [View]
[Download]

Abstract: This paper presents an optimal topology for the combination of two forward structures, attached to the same transformer and operating like a full bridge. The transformer and the output filter operate with twice of the forward switching frequency. Each one of the forward converters has a lossless commutation cell that allows for high switching frequency, high power operation and high efficiency to a wide load range. Complete mathematical analysis and experimental results will be presented in the final version of this paper.

   Analysis of ZVS-PWM Converter Based on Inductive Couplers
By W. Li; G. Maggetto; Ph. Lataire [View]
[Download]

Abstract: An inductive charging system is a DC-DC converter that is electrically separated by a Loosely Coupled Inductive Coupler (briefly, LCIC). A LCIC possesses asymmetrical leakage inductance on both the primary and the secondary side, which cannot be ignored comparing to magnetizing inductance. Basically, LCIC have two structures: single secondary coil (LCIC) and center-tapped secondary coil (CT-LCIC). When it is driven by fixed frequency phase-shifted command scheme, the LCIC-based converter behaves as a soft-switching PWM converter. According to LCIC structure and its corresponding ouput rectifier topology, the above-mentioned converters can further be classified as ZVS-PWM-FB and ZVS-PWM-CT converters. Both of them take use of the parasitic capacitors of the switches and the leakage inductances of LCIC to realize soft-switching. Apart from large asmmetrical, leakage inductances exist in its primary and seconday side of LCIC, for CT-LCIC, those two secondary leakage inductances will couple themselves and exhibits “lekage inductance coupling effect”. Such large aymmetrical leakage inductances on LCIC and the leakage inductance coupling on CT-LCIC have strong influence on the behaviors of a PWM converters, and thus, should be investigated.

   Auxiliary Resonant DC Link Soft Switching Inverter for AC Servo Motor
By J. Yoshitsugu; M. Ando; K. Inoue; E. Hiraki; M. Nakaoka [View]
[Download]

Abstract: This paper presents an auxiliary active quasi-resonant DC link snubber-assisted three phase voltage source type soft-switching inverter using IPM (Intelligent Power Module) for AC servo motor drive applications. The operation of this quasi-resonant DC link snubber circuit and its circuit parameter design approach are described and three phase voltage source soft switching inverter using a quasiresonant DC link snubber treated here is discussed from an experimental point of view. In addition to this, the motor current and the motor speed response under the soft switching inverter are compared with that of the conventional hard switching inverter. The effectiveness of the soft switching inverterfed permanent magnet AC servo motor drive system is evaluated on the basis of the common mode current in the inverter driven motor side as compared with that of the conventional hard switching inverter-fed permanent AC servo motor drive system.

   Characteristic analysis of ZVS-HB type high frequency resonant inverter according to the variable capacitance of the DC voltage source separation capacitor
By J. S. Won; D. H. Kim; D. Y. Jung; B. S. Lee; J. H. Kim [View]
[Download]

Abstract: This paper presents about an example of circuit design and characteristics of inverter according to the variable capacitance of the DC voltage source separation capacitor used in ZVS-HB type high frequency resonant inverter. The soft switching technology known as ZVS is used to reduce turn off loss at switching. In the event the capacitance of the DC voltage source separation capacitor is varied, the analysis of inverter circuit has generally described by using normalized parameter and operating characteristics have been evaluated in terms of switching frequency and parameters. According to the calculated characteristics value, a method of the circuit designs and operating characteristic of the inverter is also presented in this paper. In addition, this paper proves the validity of theoretical analysis through the experiment. This proposed inverter shows that it can be practically used in future as power source system for the lighting equipment of discharge lamp, DC-DC converter etc.

   Design and Implementation of a Quasi-Resonant DC Link Converter
By P. Karlsson; M. Bojrup; M. Alaküla; L. Gertmar [View]
[Download]

Abstract: In this paper, a passively clamped quasi-resonant DC link converter is analysed, implemented and evaluated in a battery charger application. Design expressions for selection of passive component values, based mainly on the specified maximum output voltage derivative and the duration of the zero voltage interval, are given. Design of the inductive components and selection of appropriate power semiconductors for the quasi-resonant DC link are investigated. The main problems regarding power electronic design of these components are also discussed. The quasi-resonant DC link waveforms are measured and the converter efficiency is measured and compared to a hard switched case.

   Design of Soft Switched PWM Converter Controlled by PWM IC
By G-B. Joung [View]
[Download]

Abstract: This paper describes the operation and characteristics of soft switched PWM DC-DC converter. The soft switched PWM DC-DC converter using conventional PWM IC was designed and experimented. In this design, the control circuits, which are added a few parts of circuit elements, are very simple because the converter is operated by conventional PWM control IC. Therefore the control scheme will be as simple as conventional PWM converter and the soft switching of the switches is always satisfied.

   Diesel Emission Control System using PWM High Frequency Inverter
By S. Kubota; N. Ogawa; Y. Shimaoka; Y. Hatanaka [View]
[Download]

Abstract: This paper describes the diesel emission control system, and the soft switching PWM high frequency inverter. In order to equip a diesel engine with the diesel emission system, an output power in the proposed inverter is controlled according to change of the generating power of an engine. In this paper, the characteristics of this inverter is analyzed

   Enhanced Analysis and Design of a 3-Level ZVZCS DC/DC Converter
By N. Fröhleke; M. Schniedermann [View]
[Download]

Abstract: An enhanced analysis for a recently proposed, 3-level half bridge featuring reduced voltage stress and soft switching of the transistors is presented revealing additional network states and yielding more exact dc-voltage ratio. Practical design issues such as downsizing a bulky auxiliary capacitor and a flying capacitor is addressed after stress quantities are given. Experimental results gained on a 140A/4kW prototype for welding power supplies are presented.

   Far Infrared Rays Radiant Heating using PWM High Frequency Inverter
By H. Tanaka; H. Sadakata; M. A. AL; C. E. Hui; A. Okuno; M. Nakaoka [View]
[Download]

Abstract: This paper presents an innovative prototype of a conceptual electromagnetic induction type far infrared rays radiant heating appliance using voltage fed quasi-resonant ZVS-PWM high frequency inverter which can operate at constant frequency variable power regulation scheme. This consumer power appliance is more cost effective because of high frequency, safety, cleanliness, compactness and rapid temperature response.

   Industrial 20kHz/150kVA insulated Soft switching DC-DC converter
By J.P. Lavieville; P. Baudesson; L. Gilbert; J-M. Bodson [View]
[Download]

Abstract: Higher switching frequencies are the key to reduce the size and weight of passive energy storage elements. The drawback of this action is the increasing of the switching losses. One possible solution to the inevitable compromise frequency/losses is the use of soft switching techniques. The present paper highlights the analysis and the results obtained of an efficient 150 KVA DC-DC converter including a high frequency ferrite transformer using zero switching loss. These results are not considered final by the authors, but rather as a beginning of a series of studies base on this family of topology.

   Modelling, Analysis and design of a three-phase resonant converter.
By S. Akre; M. Egan [View]
[Download]

Abstract: A three-phase resonant dc-dc conversion topology is presented and analyzed. The converter is analyzed using a linear per-phase equivalent circuit model. Standard star-delta, delta-delta or deltastar connection can be employed for the isolation transformers. A systematic step-by-step design procedure is given. The impact of the star-delta or the delta-star configuration, on the converter performance is studied and the results are presented. Advantages of the converter includes softswitching for all of the inverter switches, low input and output ripple, a narrow control frequency range and use of leakage inductance as part of resonant inductor. The topology is suitable for highpower, high-frequency, high-voltage applications.

   Modular ZVZCS High Current, Low Voltage Power Converter [13kA,16V]
By F. Bordry; V. Montabonnet; H. Thiesen; G. Kniegl; R. Pauls; B. Wolfes [View]
[Download]

Abstract: The Large Hadron Collider (LHC) is the next accelerator being constructed at the European Laboratory for Particle Physics (CERN). The superconducting LHC particle accelerator requires high currents (13kA) and relatively low voltages (16 V) for its magnets. This paper describes the development and the production of a [13kA, 16V] power converter. The converter is made with a modular concept with five current sources [3.25kA,16V] in parallel. The 3.25kA sources are built as plug-in modules: a diode rectifier on the AC mains, a Zero Voltage Zero Current Switching (ZVZCS) inverter working at 25 kHz and an output stage. The obtained performance is presented and discussed.

   Multiresonant Converter: 12Kw Prototype For Batteries And Equipments
By B. Dakyo; J. M. Blaquiere; P. Reghem [View]
[Download]

Abstract: The multiresonant concept is adopted for soft-switching benefits. The theoretical analysis of the converter are tied to mode multiplicity and the knowledge of converter behaviour in frequency domain. We propose very efficient system theory and practice wich takes in account transformer leakage inductance for a userdefined high frequency range of operation.

   New Active Resonant Topology Of Soft Switching 3Phase Pfc Rectifier
By E. Hiraki; M. Yoshida; M. Nakaoka [View]
[Download]

Abstract: This paper presents a new active quasi-resonant snubber circuit topology (Auxiliary Quasi-Resonant Commutation Block-Link Snubber; ARCB) which is suitable for the voltage source type three phase PWM inverters / PFC rectifier, which can operate under a principle of Zero Voltage Soft Switching (ZVS) commutation. Its operating principle, and the steady-state operationg performances of the digitally-controlled three phase soft switching PWM-PFC rectifier system with an instantaneous power feedback scheme are discribed in this paper. The circuit parameter design method are illustrated and evaluated on the basis of computer-aided simulation analysis.

   Quantitative Analysis on Switching Surge in Soft-switching Converters
By T. Higashi [View]
[Download]

Abstract: Noise characteristics on switching surge in Soft-switching converter family such as Current-mode resonant type, Voltage-mode resonant type, Active-clamp type have been quantitatively studied by experiment and analysis. The mechanisms of noise generation for each converter are revealed using very accurate high-frequency model, and noise characteristics have been compared among them.

   Reduction of Linearity Range of SVM in Soft Switching Converters
By A. Radan [View]
[Download]

Abstract: The duration of Zero Voltage Transitions (ZVT) in soft switching converters restricts the minimum duration of voltage vectors of Space Vector PWM (SVPWM) which can be switched. This affects the linearity range of space vector modulation in soft switching converters. This paper investigates the restrictions imposed by the duration of ZVT on SVPWM resulting in reduction of the linearity range of modulation in these converters. The conventional continuous SVPWM and an optimised discontinuous SVPWM are compared with each other regarding maximum available linear modulation index. The results show that the discontinuous SVPWM makes a higher maximum linear modulation index available in soft switching converters, but this maximum can not be reached the value 1.15 of hard switching converters.

   Review of modelling methodologies for high-order resonant converters
By M. P. Foster; H. I. Sewell; D. A. Stone; C. M. Bingham. [View]
[Download]

Abstract: In recent years, the importance of resonant converter topologies to the power conversion industry has increased significantly, with the requirement for increasingly smaller power supplies for more compact electronic equipment, and higher efficiency supplies for increased battery life and/or to meet environmental constraints. Furthermore, the improved performance characteristics that can be obtained by employing high-order tank circuits have attracted interest in complex resonant power circuitry. However, hand-in-hand with the increased complexity of such high-order resonant converters, comes the increased difficulty in modelling of their performance at the design stage. This is predominantly due to the fact that appropriate converter topologies exhibit several degrees of freedom, and also tend to have long settling times compared to the switching period. This paper aims to contrast and compare a number of techniques that have been proposed to address these, and other pertinent issues.

   Soft-Switching Inverter Topologies for Linear Motor Drive Applications
By J. M.A. Myrzik; J. L. Duarte; K. Wijnands [View]
[Download]

Abstract: In order to achieve higher power density, higher efficiency and lower EMI and sub-harmonics ratings soft-transition techniques are applied in DC -AC converter design. This kind of soft-switching technique enables the implementation of low-noise PWM waveforms by means of auxiliary switches. A comparison study of two recently developed soft-switching inverter topologies is carried out to characterize the stress and size of the inverter components and the loss mechanisms. The application for high-speed linear motors (> 1.0m/sec) stands in the foreground. Limitations of switching frequency and duty cycle gives a predication of the maximum output current bandwidth and power output.

   The Power Regulator With Inherent Overload Protection
By M. Vuksic; S. M. Beroš [View]
[Download]

Abstract: The implementation of the half bridge ZVS multiresonant DC/DC converter in mains powered power regulator application is presented. Converter is powered with the full wave rectified mains voltage only and loaded with resistive load. A prototype development is based upon performed analysis of the DC transfer ratio and experimental measurement of the small signal transfer function. The prototype delivers 100W at 12V RMS output voltage at full load. The power delivered to load can be dimmed down to zero. The converter shows inherent overload protection. The power regulator is suitable for the resistive loads with high initial current requirements such as halogen lamps.

   Three-Phase Current-Fed PWM Converter with AC Input Side Commutation I
By M. Ishibashi; Y. Konishi; E. Hiraki; M. Nakaoka [View]
[Download]

Abstract: This paper presents a new three-phase current-fed soft-switching PWM converter with commutation inductor and resonant snubber. This converter utilizes two types of switching commutation schemes to improve the PWM current utilization rate. It is described that this converter has effective performance of low THD and high current utilization rate by computer simulation results.

   Two New Concepts Bridging Between SRC and PWM Converters
By W. Li; G. Maggetto; Ph. Lataire [View]
[Download]

Abstract: The resonant converters are not transparent. With the introduction of LCIC or CT-LCIC, the SRCs will be too complicated to be analytically solved. When operating above the resonant frequency, the SRCs behave similar to their PWM counterparts. The resonant capacitor can be considered as “negative inductance” that can be combined the leakage inductance of the resonant tank; thus, SRC (fs>1) is simplified as PWM converter. When it is driven by fixed frequency phase-shifted command scheme, the SRC (fs>1) may operate under DCM mode, where two resonant frequencies affect the converter’s behavior. The concept of “Switching frequency shift” can equivalent such two resonant frequencies effect with higher switching frequency under one resonant frequency. By deploying those two concepts, the steady-state characteristics of SRCs (fs>1) can be well approximated. The results are experimentally verified.

EPE 2001 - Topic 02a: Soft Switching Converters (Resonant, ZVS, ZCS)
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2001 - Conference > EPE 2001 - Topic 02: POWER ELECTRONICS CONVERTER CIRCUITS > EPE 2001 - Topic 02a: Soft Switching Converters (Resonant, ZVS, ZCS)
	[return to parent folder]

	A Comparison Of LCC Inverters With Resonant Current Control As A HPS.. By F. Rodríguez; J. Ribas; J. Cardesín; J. M. Alonso; E. L. Corominas; A. Calleja; J. García; M. Rico-Secades	[View] [Download]
Abstract: The goal of this paper is to compare the LCC-Series Parallel Resonant Inverter with the LCC-Parallel Series Resonant Inverter, both working with the same control method (Resonant Current Control). This control forces the inverter to operate with optimum commutations and without handling any reactive energy, thus minimising both switching and conduction losses. Also, a graphic design method to calculate the resonant tank elements for both, the SP and the PS topologies is shown. This method is based on the Output–power vs Load–resistance Optimum Commutations curves.

	A High PFC Doubler Half Bridge Boost without Losses of Commutation By R. M. Finzi Neto; J. B. Vieira Jr.; L.H.B.S.C Barreto; E.A. Coelho; Luiz C. Freitas	[View] [Download]
Abstract: This paper presents a High Power Factor Doubler Half Bridge Boost Converter without losses of commutation to obtain high output voltages with a simple control. A detailed analysis of its functioning is presented. Simulation results of the proposed topology are presented to confirm the proposed ideas. In order to corroborate this approach, mathematical analysis and experimental results are presented.

	An Optimal Lossless Commutation PWM Two Level Forward Converter ... By R. M. Finzi Neto; J. B. Vieira Jr.; E.A. Coelho; L.H.B.S.C Barreto; V.J. Farias; L. C. Freitas	[View] [Download]
Abstract: This paper presents an optimal topology for the combination of two forward structures, attached to the same transformer and operating like a full bridge. The transformer and the output filter operate with twice of the forward switching frequency. Each one of the forward converters has a lossless commutation cell that allows for high switching frequency, high power operation and high efficiency to a wide load range. Complete mathematical analysis and experimental results will be presented in the final version of this paper.

	Analysis of ZVS-PWM Converter Based on Inductive Couplers By W. Li; G. Maggetto; Ph. Lataire	[View] [Download]
Abstract: An inductive charging system is a DC-DC converter that is electrically separated by a Loosely Coupled Inductive Coupler (briefly, LCIC). A LCIC possesses asymmetrical leakage inductance on both the primary and the secondary side, which cannot be ignored comparing to magnetizing inductance. Basically, LCIC have two structures: single secondary coil (LCIC) and center-tapped secondary coil (CT-LCIC). When it is driven by fixed frequency phase-shifted command scheme, the LCIC-based converter behaves as a soft-switching PWM converter. According to LCIC structure and its corresponding ouput rectifier topology, the above-mentioned converters can further be classified as ZVS-PWM-FB and ZVS-PWM-CT converters. Both of them take use of the parasitic capacitors of the switches and the leakage inductances of LCIC to realize soft-switching. Apart from large asmmetrical, leakage inductances exist in its primary and seconday side of LCIC, for CT-LCIC, those two secondary leakage inductances will couple themselves and exhibits “lekage inductance coupling effect”. Such large aymmetrical leakage inductances on LCIC and the leakage inductance coupling on CT-LCIC have strong influence on the behaviors of a PWM converters, and thus, should be investigated.

	Auxiliary Resonant DC Link Soft Switching Inverter for AC Servo Motor By J. Yoshitsugu; M. Ando; K. Inoue; E. Hiraki; M. Nakaoka	[View] [Download]
Abstract: This paper presents an auxiliary active quasi-resonant DC link snubber-assisted three phase voltage source type soft-switching inverter using IPM (Intelligent Power Module) for AC servo motor drive applications. The operation of this quasi-resonant DC link snubber circuit and its circuit parameter design approach are described and three phase voltage source soft switching inverter using a quasiresonant DC link snubber treated here is discussed from an experimental point of view. In addition to this, the motor current and the motor speed response under the soft switching inverter are compared with that of the conventional hard switching inverter. The effectiveness of the soft switching inverterfed permanent magnet AC servo motor drive system is evaluated on the basis of the common mode current in the inverter driven motor side as compared with that of the conventional hard switching inverter-fed permanent AC servo motor drive system.

	Characteristic analysis of ZVS-HB type high frequency resonant inverter according to the variable capacitance of the DC voltage source separation capacitor By J. S. Won; D. H. Kim; D. Y. Jung; B. S. Lee; J. H. Kim	[View] [Download]
Abstract: This paper presents about an example of circuit design and characteristics of inverter according to the variable capacitance of the DC voltage source separation capacitor used in ZVS-HB type high frequency resonant inverter. The soft switching technology known as ZVS is used to reduce turn off loss at switching. In the event the capacitance of the DC voltage source separation capacitor is varied, the analysis of inverter circuit has generally described by using normalized parameter and operating characteristics have been evaluated in terms of switching frequency and parameters. According to the calculated characteristics value, a method of the circuit designs and operating characteristic of the inverter is also presented in this paper. In addition, this paper proves the validity of theoretical analysis through the experiment. This proposed inverter shows that it can be practically used in future as power source system for the lighting equipment of discharge lamp, DC-DC converter etc.

	Design and Implementation of a Quasi-Resonant DC Link Converter By P. Karlsson; M. Bojrup; M. Alaküla; L. Gertmar	[View] [Download]
Abstract: In this paper, a passively clamped quasi-resonant DC link converter is analysed, implemented and evaluated in a battery charger application. Design expressions for selection of passive component values, based mainly on the specified maximum output voltage derivative and the duration of the zero voltage interval, are given. Design of the inductive components and selection of appropriate power semiconductors for the quasi-resonant DC link are investigated. The main problems regarding power electronic design of these components are also discussed. The quasi-resonant DC link waveforms are measured and the converter efficiency is measured and compared to a hard switched case.

	Design of Soft Switched PWM Converter Controlled by PWM IC By G-B. Joung	[View] [Download]
Abstract: This paper describes the operation and characteristics of soft switched PWM DC-DC converter. The soft switched PWM DC-DC converter using conventional PWM IC was designed and experimented. In this design, the control circuits, which are added a few parts of circuit elements, are very simple because the converter is operated by conventional PWM control IC. Therefore the control scheme will be as simple as conventional PWM converter and the soft switching of the switches is always satisfied.

	Diesel Emission Control System using PWM High Frequency Inverter By S. Kubota; N. Ogawa; Y. Shimaoka; Y. Hatanaka	[View] [Download]
Abstract: This paper describes the diesel emission control system, and the soft switching PWM high frequency inverter. In order to equip a diesel engine with the diesel emission system, an output power in the proposed inverter is controlled according to change of the generating power of an engine. In this paper, the characteristics of this inverter is analyzed

	Enhanced Analysis and Design of a 3-Level ZVZCS DC/DC Converter By N. Fröhleke; M. Schniedermann	[View] [Download]
Abstract: An enhanced analysis for a recently proposed, 3-level half bridge featuring reduced voltage stress and soft switching of the transistors is presented revealing additional network states and yielding more exact dc-voltage ratio. Practical design issues such as downsizing a bulky auxiliary capacitor and a flying capacitor is addressed after stress quantities are given. Experimental results gained on a 140A/4kW prototype for welding power supplies are presented.

	Far Infrared Rays Radiant Heating using PWM High Frequency Inverter By H. Tanaka; H. Sadakata; M. A. AL; C. E. Hui; A. Okuno; M. Nakaoka	[View] [Download]
Abstract: This paper presents an innovative prototype of a conceptual electromagnetic induction type far infrared rays radiant heating appliance using voltage fed quasi-resonant ZVS-PWM high frequency inverter which can operate at constant frequency variable power regulation scheme. This consumer power appliance is more cost effective because of high frequency, safety, cleanliness, compactness and rapid temperature response.

	Industrial 20kHz/150kVA insulated Soft switching DC-DC converter By J.P. Lavieville; P. Baudesson; L. Gilbert; J-M. Bodson	[View] [Download]
Abstract: Higher switching frequencies are the key to reduce the size and weight of passive energy storage elements. The drawback of this action is the increasing of the switching losses. One possible solution to the inevitable compromise frequency/losses is the use of soft switching techniques. The present paper highlights the analysis and the results obtained of an efficient 150 KVA DC-DC converter including a high frequency ferrite transformer using zero switching loss. These results are not considered final by the authors, but rather as a beginning of a series of studies base on this family of topology.

	Modelling, Analysis and design of a three-phase resonant converter. By S. Akre; M. Egan	[View] [Download]
Abstract: A three-phase resonant dc-dc conversion topology is presented and analyzed. The converter is analyzed using a linear per-phase equivalent circuit model. Standard star-delta, delta-delta or deltastar connection can be employed for the isolation transformers. A systematic step-by-step design procedure is given. The impact of the star-delta or the delta-star configuration, on the converter performance is studied and the results are presented. Advantages of the converter includes softswitching for all of the inverter switches, low input and output ripple, a narrow control frequency range and use of leakage inductance as part of resonant inductor. The topology is suitable for highpower, high-frequency, high-voltage applications.

	Modular ZVZCS High Current, Low Voltage Power Converter [13kA,16V] By F. Bordry; V. Montabonnet; H. Thiesen; G. Kniegl; R. Pauls; B. Wolfes	[View] [Download]
Abstract: The Large Hadron Collider (LHC) is the next accelerator being constructed at the European Laboratory for Particle Physics (CERN). The superconducting LHC particle accelerator requires high currents (13kA) and relatively low voltages (16 V) for its magnets. This paper describes the development and the production of a [13kA, 16V] power converter. The converter is made with a modular concept with five current sources [3.25kA,16V] in parallel. The 3.25kA sources are built as plug-in modules: a diode rectifier on the AC mains, a Zero Voltage Zero Current Switching (ZVZCS) inverter working at 25 kHz and an output stage. The obtained performance is presented and discussed.

	Multiresonant Converter: 12Kw Prototype For Batteries And Equipments By B. Dakyo; J. M. Blaquiere; P. Reghem	[View] [Download]
Abstract: The multiresonant concept is adopted for soft-switching benefits. The theoretical analysis of the converter are tied to mode multiplicity and the knowledge of converter behaviour in frequency domain. We propose very efficient system theory and practice wich takes in account transformer leakage inductance for a userdefined high frequency range of operation.

	New Active Resonant Topology Of Soft Switching 3Phase Pfc Rectifier By E. Hiraki; M. Yoshida; M. Nakaoka	[View] [Download]
Abstract: This paper presents a new active quasi-resonant snubber circuit topology (Auxiliary Quasi-Resonant Commutation Block-Link Snubber; ARCB) which is suitable for the voltage source type three phase PWM inverters / PFC rectifier, which can operate under a principle of Zero Voltage Soft Switching (ZVS) commutation. Its operating principle, and the steady-state operationg performances of the digitally-controlled three phase soft switching PWM-PFC rectifier system with an instantaneous power feedback scheme are discribed in this paper. The circuit parameter design method are illustrated and evaluated on the basis of computer-aided simulation analysis.

	Quantitative Analysis on Switching Surge in Soft-switching Converters By T. Higashi	[View] [Download]
Abstract: Noise characteristics on switching surge in Soft-switching converter family such as Current-mode resonant type, Voltage-mode resonant type, Active-clamp type have been quantitatively studied by experiment and analysis. The mechanisms of noise generation for each converter are revealed using very accurate high-frequency model, and noise characteristics have been compared among them.

	Reduction of Linearity Range of SVM in Soft Switching Converters By A. Radan	[View] [Download]
Abstract: The duration of Zero Voltage Transitions (ZVT) in soft switching converters restricts the minimum duration of voltage vectors of Space Vector PWM (SVPWM) which can be switched. This affects the linearity range of space vector modulation in soft switching converters. This paper investigates the restrictions imposed by the duration of ZVT on SVPWM resulting in reduction of the linearity range of modulation in these converters. The conventional continuous SVPWM and an optimised discontinuous SVPWM are compared with each other regarding maximum available linear modulation index. The results show that the discontinuous SVPWM makes a higher maximum linear modulation index available in soft switching converters, but this maximum can not be reached the value 1.15 of hard switching converters.

	Review of modelling methodologies for high-order resonant converters By M. P. Foster; H. I. Sewell; D. A. Stone; C. M. Bingham.	[View] [Download]
Abstract: In recent years, the importance of resonant converter topologies to the power conversion industry has increased significantly, with the requirement for increasingly smaller power supplies for more compact electronic equipment, and higher efficiency supplies for increased battery life and/or to meet environmental constraints. Furthermore, the improved performance characteristics that can be obtained by employing high-order tank circuits have attracted interest in complex resonant power circuitry. However, hand-in-hand with the increased complexity of such high-order resonant converters, comes the increased difficulty in modelling of their performance at the design stage. This is predominantly due to the fact that appropriate converter topologies exhibit several degrees of freedom, and also tend to have long settling times compared to the switching period. This paper aims to contrast and compare a number of techniques that have been proposed to address these, and other pertinent issues.

	Soft-Switching Inverter Topologies for Linear Motor Drive Applications By J. M.A. Myrzik; J. L. Duarte; K. Wijnands	[View] [Download]
Abstract: In order to achieve higher power density, higher efficiency and lower EMI and sub-harmonics ratings soft-transition techniques are applied in DC -AC converter design. This kind of soft-switching technique enables the implementation of low-noise PWM waveforms by means of auxiliary switches. A comparison study of two recently developed soft-switching inverter topologies is carried out to characterize the stress and size of the inverter components and the loss mechanisms. The application for high-speed linear motors (> 1.0m/sec) stands in the foreground. Limitations of switching frequency and duty cycle gives a predication of the maximum output current bandwidth and power output.

	The Power Regulator With Inherent Overload Protection By M. Vuksic; S. M. Beroš	[View] [Download]
Abstract: The implementation of the half bridge ZVS multiresonant DC/DC converter in mains powered power regulator application is presented. Converter is powered with the full wave rectified mains voltage only and loaded with resistive load. A prototype development is based upon performed analysis of the DC transfer ratio and experimental measurement of the small signal transfer function. The prototype delivers 100W at 12V RMS output voltage at full load. The power delivered to load can be dimmed down to zero. The converter shows inherent overload protection. The power regulator is suitable for the resistive loads with high initial current requirements such as halogen lamps.

	Three-Phase Current-Fed PWM Converter with AC Input Side Commutation I By M. Ishibashi; Y. Konishi; E. Hiraki; M. Nakaoka	[View] [Download]
Abstract: This paper presents a new three-phase current-fed soft-switching PWM converter with commutation inductor and resonant snubber. This converter utilizes two types of switching commutation schemes to improve the PWM current utilization rate. It is described that this converter has effective performance of low THD and high current utilization rate by computer simulation results.

	Two New Concepts Bridging Between SRC and PWM Converters By W. Li; G. Maggetto; Ph. Lataire	[View] [Download]
Abstract: The resonant converters are not transparent. With the introduction of LCIC or CT-LCIC, the SRCs will be too complicated to be analytically solved. When operating above the resonant frequency, the SRCs behave similar to their PWM counterparts. The resonant capacitor can be considered as “negative inductance” that can be combined the leakage inductance of the resonant tank; thus, SRC (fs>1) is simplified as PWM converter. When it is driven by fixed frequency phase-shifted command scheme, the SRC (fs>1) may operate under DCM mode, where two resonant frequencies affect the converter’s behavior. The concept of “Switching frequency shift” can equivalent such two resonant frequencies effect with higher switching frequency under one resonant frequency. By deploying those two concepts, the steady-state characteristics of SRCs (fs>1) can be well approximated. The results are experimentally verified.