• Journal of Welding and Joining
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• v.21 no.1
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• pp.35-41
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• 2003

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1064-1066
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• 2002

This paper proposes a new prototype auxiliary resonant DC link(ARDCL)snubber circuit and deals with its power loss on the basis of actually measured conduction loss characteristic of switching device module. Voltage type soft switching three phase inverter using proposed ARDCL snubber circuit is presented along with its performance evaluations. And, the power loss analysis of three phase hard and soft switching inverter are carried out from the point of simulation and experimental results.

• Journal of Power System Engineering
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• v.13 no.2
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• pp.42-48
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• 2009

본 실험에서는 왕복동식 수소 압축 시스템에서 다양한 스너버 압력변화와 스너버 효과를 조사가 수행되었다. 압력값은 실험적인 방법으로 스너버 시스템에서 각각 6군데에서 압력 값을 측정하였다. 그리고 아크릴 스너버에서의 입, 출구의 압력진폭은 FFT로 얻어진다. 맥동압 감소는 결과의 입, 출구의 진폭으로써 계산되어진다. 이는 각각의 모터 주파수 30, 40, 50Hz에서 각각 58.248%, 57.026%, 56.871%의 맥동압 감소가 일어난다. 압력 손실은 각각의 모터주파수 30, 40, 50Hz에서 0.960%, 1.533%, 1.965% 손실값이 발생한다. 수치해석은 스너버 내부 모든 구역에의 압력 정보를 보여준다. 실험과 수치해석의 결과를 비교하면 좋은 일치성을 보인다. 그렇기 때문에 수치해석으로 구한 압력 예측값은 왕복등식 수소 압축 시스템의 스너버 성능을 포함하는 다양한 수학적 식에 적용가능하다.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.37 no.7
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• pp.442-447
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• 1988

Saturable reactor-resistor pair is proposed as a part of snubber and applied to a hard commutation chopper. SCR turn off process is modeled to simulate the hard commutation chopper. State equations are derived for each mode of the chopper and they are solved by Runge-Kutta 4th order method. It is shown that the reverse voltage spike and reverse dv/dt can be minimized by applying saturable reactor-resistor pair to the chopper which controls peak reverse recovery current and damping factor. Saturable reactor-resistor pair can be used to reduced SCR power loss and value of snubber capacitor and can be applied to high power thyristor devices.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.450-452
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• 1996

In this paper, the authors propose a DC-DC boost converter of high efficiency by partial resonant switching mode, the switching devices in a proposed circuit are operated with soft switching and the control technique of those is simplified for switch to drive in constant duty cycle. The circuit has a merit which is taken to increase of efficiency, as it makes to a regeneration at input source of accumulated energy in snubber condenser without loss of snubber inconventional circuit. The proposed converter is deemed the most suitable for high power applications where the power switching devices are used.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.447-449
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• 1996

The main objective of this paper is to increase the efficiency, to eliminate the harmonics wave and to acomplish the zero voltage regulation of the output voltage. To accomplish the goal, DC-to-DC converter model with ERS(Energy Recovery Snubber) is developed. And, to realize the detail purpose, we are used ZVS soft switching snubber, ripple steering filter and, function control law etc.. So, we presented to show superior operation of this convertor with the zero voltage regulation function.

• Proceedings of the KIPE Conference
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• 1997.07a
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• pp.417-422
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• 1997

This paper proposed that a AC-DC Converter topology of high power factor with soft switching mode operates with four chopper connecting a number of parallel circuit. To improve these, a large number of soft switching topologies included a resonant circuit have been proposed. And, some simulative results on computer is included to confirm the validity of the analytical results. The partial resonant circuit makes use of a inductor using step up and a condenser of loss-less snubber. The result is that the switching loss is very low and the efficiency of system is high. And the snubber condenser used in partial resonant circuit makes charging engergy regenerated at input power source for resonant operation. The proposed conversion system is deemed the most suitable for high power applications where the power switching devices are used.

• Proceedings of the KIPE Conference
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• 1997.07a
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• pp.251-255
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• 1997

The conventional high frequency phase-shifted full bridge dc/dc converter has a disadvantage that a circulating current flows through transformer and switching devices during the freewheeling interval. Due to this circulating current, RMS current stress, conduction losses of transformer and switching devices are increased. To alleviate this problem, this paper provides a circulating current free type high frequency soft switching phase-shifted full bridge (FB) dc/dc converter with energy recovery snubber (ERS) attached at the secondary side of transformer. The energy recovery snubber (ERS) adopted in this study is consisted of three fast recovery diode(Ds1, DS2, Ds3), two resonant capacitor (Cs1, Cs2)

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.189-192
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• 2001

This paper proposed that an AC-DC converter system using multiple buck-chopper operates with four choppers connecting to a number of parallel circuits. To improve these, a large number of soft switching topologies included a resonant circuit have been proposed. And, some simulative results on computer are included to confirm the validity of the analytical results. The partial resonant circuit makes use of an inductor using step-down and a condenser of loss-less snubber. The result is that the switching loss is very low and the efficiency of system is high. And the snubber condenser used in a partial resonant circuit makes charging energy regenerated at input power source for resonant operation. The proposed conversion system is deemed the most suitable for high power applications where the power switching devices are used.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.5
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• pp.448-456
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• 2000

For piping line systems associated with a double-acting reciprocating compressor, an analytical study has been made on the gas pulsation in piping lines and its effects on the compressor performance. The transfer matrix which relates mass flow rate to the gas pulsation downstream of the compressor valve can be obtained by an acoustic model for piping line systems which include snubber and after-cooler with the aid of four pole theory Since mass flow rate is affected by the pressure pulsation in the pressure plenum, while the latter being determined by the former, iteration in the calculation should be made for convergence. The gas pulsation in pipings is found to have an adverse effect on the compressor's performance, and the magnitude of the gas pulsation can be lowered by increasing snubber volume.