• Proceedings of the KIEE Conference
• /
• 2005.04a
• /
• pp.134-139
• /
• 2005

This paper presents a cost effective quasi-resonant soft-switching PWM high frequency inverter with minimum circuit components. This inverter can achieve wider soft commutation, simpler power circuit configuration, smaller volumetric size, lower cost and wider power regulation range, higher-efficiency as compared with single ended quasi-resonant ZVS-PFM inverter and active voltage clamped quasi-resonant ZVS-PWM inverter. The operation principle of the proposed inverter is described on the basis of the simulation and experimental results, together with its operating performances in steady state. The operating performances of this unique proposed high frequency inverter based on ZVS and ZCS arms-related soft commutation principle is evaluated and discussed as compared with the active voltage-clamped ZVS-PWM inverter and a conventional single-ended ZVS-PFM inverter. The practical effectiveness of a novel type quasi-resonant soft-switching PWM high frequency inverter using IGBT is actually proved for consumer induction heated appliances as rice cooker, hot water producer, steamer and super heated steamer. The extended bidirectional circuit topology of quasi-resonant PWM high frequency inverter with minimum circuit components is demonstrated, which operate as the direct frequency changer.

• Proceedings of the KIEE Conference
• /
• 2001.07b
• /
• pp.1015-1019
• /
• 2001

This paper presents a novel three-phase current-fed Pulse Width Modulation converter with switched capacitor type resonant DC link commutation circuit operating PWM pattern strategy under a design consideration of low-pass filter, which can operate on the basis of the principle of zero current soft switching commutation. In the first place, the steady state operating principle of this converter with a new resonant DC link snubber circuit is described in connection with the equivalent operation circuit, together with the practical design procedure of the switched-capacitor type resonant DC link circuit is discussed from a theoretical viewpoint on the basis of a design example for high-power applications. The actively delayed time correction method to compensate distorted currents due to a relatively long resonant commutation time is newly implemented in the open loop control scheme so as to acquire the new optimum PWM pattern. Finally, the experiment of set-up in laboratory system of this converter is concretely demonstrated herein to confirm a zero current soft-switching commutation of this converter. The comparative evaluations between current-fed hard switching PWM and soft-switching PWM converters are carried out from a viewpoint of their PWM converter characteristics.

• Proceedings of the KIEE Conference
• /
• 2002.06a
• /
• pp.55-59
• /
• 2002

This paper presents a novel three-phase current-fed Pulse Width Modulation converter with switched capacitor type resonant DC link commutation circuit operating PWM pattern strategy under a design consideration of low-pass filter, which can operate on the basis of the principle of zero current soft switching commutation. In the first place, the steady state operating principle of this converter with a new resonant DC link snubber circuit is described in connection with the equivalent operation circuit, together with the practical design procedure of the switched-capacitor type resonant DC link circuit is discussed from a theoretical viewpoint on the basis of a design example for high-power applications. The actively delayed time correction method to compensate distorted currents due to a relatively long resonant commutation time is newly implemented in the open loop control scheme so as to acquire the new optimum PWM pattern. Finally, the experiment of set-up in laboratory system of this converter is concretely demonstrated herein to confirm a zero current soft-switching commutation of this converter. The comparative evaluations between current -fed hard switching PWM and soft-switching PWM converters are carried out from a viewpoint of their PWM converter characteristics.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.52 no.2
• /
• pp.49-55
• /
• 2003

This paper presents a novel three-phase current-fed Pulse Width Modulation converter with switched capacitor type resonant DC link commutation circuit operating PWM pattern strategy under a design consideration of low-pass filter, which can operate on the basis of the principle of zero current soft switching commutation. In the first place, the steady state operating principle of this converter with a new resonant DC link snubber circuit is described in connection with the equivalent operation circuit, together with the practical design procedure of the switched-capacitor type resonant DC link circuit is discussed from a theoretical viewpoint on the basis of a design example for high-power applications. The actively delayed time correction method to compensate distorted currents due to a relatively long resonant commutation time is newly implemented in the open loop control scheme so as to acquire the new optimum PWM pattern. Finally, the experiment of set-up in laboratory system of this converter is concretely demonstrated herein to confirm a zero current soft-switching commutation of this converter. The comparative evaluations between current-fed hard switching PWM and soft-switching PWM converters are carried out from a viewpoint of their PWM converter characteristics.

• Proceedings of the KIPE Conference
• /
• 2006.06a
• /
• pp.200-202
• /
• 2006

In this paper, a novel type of auxiliary active snubbing circuit assisted quasi-resonant soft-switching pulse width modulation inverter is proposed for consumer induction heating equipments. The operation principle of this high frequency inverter is described using switching modes and equivalent circuits. This newly developed series resonant high frequency inverter can regulate its high frequency output AC power under a principle of constant frequency active edge resonant soft-switching commutation by asymmetrical PWM control system. The high frequency power regulation and actual power conversion efficiency characteristics of consumer induction heating (IH) products using the proposed soft-switching pulse width modulation (PWM) series load resonant high frequency inverter evaluated. The practical effectiveness and operating performance of high frequency inverter are discussion on the basis of simulation and experimental results as compared with the conventional soft-switching high frequency inverter.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.12 no.4
• /
• pp.90-99
• /
• 1998

The DC/DC power converter increase switching frequency in order to achieve small size, a low noise, and light weight. However, the power switches have high power losses and switching stresses as the switching frequency is increased. Therefore in this paper, the author propose the Soft-Switching Forward-Flyback PWM DC/DC converter using assistant-circuit, based on forward-flyback operation of a high-frequency transformer. The proposed converter scheme is verified by simulation and experiment.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
• /
• v.5B no.2
• /
• pp.181-188
• /
• 2005

In this paper, a DC smoothing filterless soft switching pulse modulated high frequency AC power conversion circuit connected to utility. frequency AC power source is proposed for consumer induction heating hot water producer, steamer and super heated steamer. The operating principle of DC link filterless utility frequency AC-high frequency AC (HF AC) power conversion circuit defined as high frequency cycloinverter is described, which can operate under a principle of ZVS/AVT and power regulation based on alternate asymmetrical PWM in synchronization with the utility frequency single phase AC positive or negative half wave voltage. The dual mode modulation control scheme based on high frequency PWM and commercial frequency AC voltage PDM for the proposed high frequency cycloinverter are discussed to enlarge its soft switching commutation operating range for wide HF AC power regulation. This high frequency cycloinverter is developed for high frequency IH Dual Packs Heater (DPH) type boiler used in consumer and industrial fluid pipeline systems. Based on the experiment and simulation results, this high frequency cycloinverter is proved to be suitable for the consumer use IH-DPH boiler and hot water producers. The cycloinverter power regulation and power conversion efficiency characteristics are evaluated and discussed.

• Proceedings of the KIPE Conference
• /
• 2001.10a
• /
• pp.75-79
• /
• 2001

This paper presents a novel version of an active voltage clamped ZVS-PWM high frequency inverter using IGBTs for electromagnetic induction eddy current-based rolling drum heating in new generation copy and printing machines in consumer business use. The operating principle of this inverter circuit and unique features are described herein. Its constant frequency duty cycle (asymmetrical PWM) controlled voltage source quasi-resonant soft switching high frequency inverter employing IGBTs is proposed, which is capable of achieving stable and efficient zero voltage soft switching commutation over a widely specified power regulation range from full power to low power. The operating performances in a steady state of this inverter is discussed and evaluated on basis of simulation and experimental results as an induction heated roller in new generation copy machine.

• Journal of Power Electronics
• /
• v.4 no.3
• /
• pp.161-168
• /
• 2004

This paper presents a new circuit topology of high-frequency soft switching commutation boost type PWM chopper-fed DC-DC power converter with a loadside auxiliary passive resonant snubber. In the proposed boost type chopper-fed DC-DC power converter circuit operating under a principle of ZCS turn-on and ZVS turn-off commutation, the capacitor and inductor in the auxiliary passive resonant circuit works as the lossless resonant snubber. In addition to this, the voltage and current peak stresses of the power semiconductor devices as well as their di/dt or dv/dt dynamic stress can be effectively reduced by the single passive resonant snubber treated here. Moreover, it is proved that chopper-fed DC-DC power converter circuit topology with an auxiliary passive resonant snubber could solve some problems on the conventional boost type hard switching PWM chopper-fed DC-DC power converter. The simulation results of this converter are illustrated and discussed as compared with the experimental ones. The feasible effectiveness of this soft witching DC-DC power converter with a single passive resonant snubber is verified by the 5kW, 20kHz experimental breadboard set up to be built and tested for new energy utilization such as solar photovoltaic generators and fuel sell generators.

• Journal of Power Electronics
• /
• v.7 no.3
• /
• pp.181-190
• /
• 2007

This paper presents a novel circuit topology of a DC bus line series switch and parallel snubbing capacitor-assisted soft-switching PWM full-bridge inverter type DC-DC power converter with a high frequency planar transformer link, which is newly developed for high performance arc welding machines in industry. The proposed DC-DC power converter circuit is based upon a voltage source-fed H type full-bridge soft-switching PWM inverter with a high frequency transformer. This DC-DC power converter has a single power semiconductor switching device in series with an input DC low side rail and loss less snubbing capacitor in parallel with the inverter bridge legs. All the active power switches in the full-bridge arms and DC bus line can achieve ZCS turn-on and ZVS turn-off transition commutation. Consequently, the total switching power losses occurred at turn-off switching transition of these power semiconductor devices; IGBTs can be reduced even in higher switching frequency bands ranging from 20 kHz to 100 kHz. The switching frequency of this DC-DC power converter using IGBT power modules can be realized at 60 kHz. It is proved experimentally by power loss analysis that the more the switching frequency increases, the more the proposed DC-DC power converter can achieve a higher control response performance and size miniaturization. The practical and inherent effectiveness of the new DC-DC converter topology proposed here is actually confirmed for low voltage and large current DC-DC power supplies (32V, 300A) for TIG arc welding applications in industry.