• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2008.05a
• /
• pp.325-328
• /
• 2008

This paper presents a new conceptual electromagnetic induction eddy current-based stainless steel plate spiral type heater for heat exchanger or dual packs Heater in hot water system boiler steamer and super heated steamer, which is more suitable and acceptable for new generation consumer power applications. In addition, an active clamped quasi resonant PWM high frequency inverter using trench gate IGBTs power module can operate under a principle of zero voltage soft commutation with PWM is developed and demonstrated fora high efficient induction heated hot water system and boiler in the consumer power applications This consumer induction heater power appliance using active clamp soft switching PWM high-frequency inverter is evaluated and discussed on the basis of the simulation and experimental results.

• Proceedings of the KIPE Conference
• /
• 1998.10a
• /
• pp.231-234
• /
• 1998

The soft reverse recovery characteristics of P-I-N power diodes by different lifetime killer were compared in this paper. It was concluded that the best local lifetime control at N- base was achieved through the optimization of penetrated depth into the wafer by 5 MeV proton irradiation, resulting in significant soft recovery performance in our study. The results of 5∼12 MeV electron irradiation and platinum diffusion were also discussed here.

• Journal of Power Electronics
• /
• v.12 no.2
• /
• pp.268-275
• /
• 2012

Based on the standards that limit the harmonic pollution of electronic systems, the use of PFC converters is mandatory. In this paper, a new resonant bridgeless PFC converter is introduced. By eliminating the input bridge diodes, the efficiency is improved. Moreover, soft switching conditions for all of the semiconductor elements are achieved without adding any extra switches. As a result, high efficiency is attained. The proposed converter is analyzed and the theoretical and simulation results of the proposed converter are presented. In order to verify the validity of the analysis, a 40 w prototype converter is implemented and experimental results are presented. The experimental results show that high efficiency is attained while achieving a high power factor.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.50 no.9
• /
• pp.473-478
• /
• 2001

In this paper a soft switching ZVT(Zero Voltage Transition) power factor converter using active snubbers is designed to improve efficiency and reduce voltage spike and parasitic ringing. The main switch achieves ZVT and the auxiliary switch operates with ZCS. A 2KW soft switching ZVT converter is designed with switching frequency 100kHz, output voltage 400VDC. Then the designed system is realized and experimental results show that the measured efficiency and power factor are over 97.45% and 0.997 respectively with an input current THD less than 3%.

• Proceedings of the KIPE Conference
• /
• 2001.07a
• /
• pp.677-680
• /
• 2001

In this paper a soft switching ZVT power factor converter using active snubbers is designed to improve efficiency and reduce voltage spike and parastic ringing. The main switch achieves ZVT and the auxiliary switch performs with ZCS. A 2KW soft switching ZVT converter is designed with switching frequency 100kHz, output voltage 400VDC. Then the designed system is realized and experimental results shows that the measured efficiency and power factor were over $97.45\%$ and 0.997 respectively with an input current THD less than $3\%$.

• Journal of Electrical Engineering and Technology
• /
• v.9 no.5
• /
• pp.1592-1601
• /
• 2014

In this study, a novel single phase soft switched power factor correction (PFC) converter is developed with active snubber cell. The active snubber cell provides boost switch both to turn on with zero voltage transition (ZVT) and to turn off with zero current transition (ZCT). As the switching losses in the proposed converter are too low, L and C size can be reduced by increasing the operating frequency. Also, all the semiconductor devices operate with soft switching. There is no additional voltage stress in the boost switch and diode. The proposed converter has a simple structure, low cost and ease of control as well. It has a simple control loop to achieve near unity power factor with the aid of the UC3854. In this study, detailed steady state analysis of the proposed converter is presented and this theoretical analysis is verified by a prototype of 100 kHz and 500 W converter. The measured power factor and efficiency are 0.99 and 97.9% at full load.

• 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 Electrical Engineering and Technology
• /
• v.13 no.6
• /
• pp.2553-2560
• /
• 2018

In Korea, there are no instances where a hydrogen fuel cell power generation system has been used in a railway vehicle. Only the basic topology has been studied. In the previous study, conventional converters using a single switch were applied to the fuel cell power generation system. Therefore, current stress on the switch at converter on-off transitions would be large when controlling a large-capacity railway vehicle. In addition, since the input side ripple is also large, there is a problem with a shortening of the lifetime of both the fuel cell power generation system and the inductor. In this paper, a soft-switching transformer inductor boost converter for fuel cell powered railway vehicles was proposed. A technique to reduce both the switching current stress generated during on-off transitions, and the input ripple current flowing in the inductor were studied. The soft-switching TIB converter uses a transformer-type inductor to configure the entire circuit in an interleaved method, and reduces both input current ripple and the current ripple of the inductor and switch.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2005.11a
• /
• pp.377-382
• /
• 2005

This paper presents two new circuit topologies of DC bus lineside active edge resonant snubber assisted soft-switching PWM full-bridge DC-DC converter acceptable for either utility AC 200V-rms or AC 400V-rms input voltage source. One topology of proposed DC-DC converters is composed of a typical voltage source-fed full-bridge high frequency PWM inverter using DC busline side series power semiconductor switching devices with the aid of a parallel capacitive lossless snubber. All the active power switches in the full-bridge arms and DC busline can achieve ZCS turn-on and ZVS turn-off commutations and the total turn-off switching power losses of all active switches can be reduced for high-frequency switching action. It is proved that the more the switching frequency of full-bridge soft switching inverter increases, the more soft-switching PWM DC-DC converter with a hish frequency transformer link has remarkable advantages for its efficiency and power density as compared with the conventional hard-switching PWM inverter type DC-DC converter

• The Transactions of the Korean Institute of Power Electronics
• /
• v.23 no.3
• /
• pp.190-198
• /
• 2018

This paper proposes a nonisolated, bidirectional, soft-switching DC - DC converter with PWM plus phase shift (PPS) control. The proposed converter has an input-parallel/output-series configuration and can achieve the interleaving effect and high voltage gains, resulting in decreased voltage ratings in all related devices. The proposed converter can operate under zero-voltage switching (ZVS) conditions for all switches in continuous conduction mode. The power flow of the proposed converter can be controlled by changing the phase shift angle, and the duty is controlled to balance the voltage of four high voltage side capacitors. The PPS control device of the proposed converter is simple in structure and presents symmetrical switching patterns under a bidirectional power flow. The PPS control also ensures ZVS during charging and discharging at all loads and equalizes the voltage ratings of the output capacitors and switches. To verify the validity of the proposed converter, an experimental investigation of a 2 kW prototype is performed in both charging and discharging modes under different load conditions and a bidirectional power flow.