• 전력전자학회논문지
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• 제4권3호
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• pp.304-309
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• 1999

본 논문에서는 새로운 24펄스 다이오드 정류기 시스템을 제안한다. 제안하는 다이오드 정류기 시스템은 기존의 직렬형 12펄스 다이오드 정류기에 수동의 보조회로를 추가함으로서 구성되어지고, 입력전류는 제 22차까지의 고조파가 제거되어 거의 정현파에 가까운 전류 파형을 얻는다. 또한, 출력 전압은 n=24k, k=1,2,3... 의 고조파 성분을 갖는 24펄스 특성를 나타낸다. 더욱이, 이 보조회로의 용량은 출력용량에 비하여 매우 작으며, 능동 스위칭소자를 사용하지 않으므로 외란에 강하고 구현이 간단하다. 따라서, 본 방식은 중·대용량급의 고전압 비제어(uncontrolled) 직류전원이 필요한 인버터나 무정전 전원장치등의 앞단에서 입력고조파의 저감에 경제적이고 효율적이다. 220V, 3KVA 정류기 시스템의 실험을 통하여 제안한 시스템의 타당성을 검증하였다.

• 전기학회논문지
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• 제65권11호
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• pp.1919-1924
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• 2016

In general, Diode rectifier has been applied to DC traction power supply system. Diode has some characteristics which is voltage drop in inverse proportion of load because of non-controlled switch, and cannot flow a current in reverse bias. So, voltage drop occurs frequently, and regenerated power cannot use in substation. The PWM rectifier is able to control output voltage constantly to reduce voltage drop and to use regeneration power without additional inverter. This paper proposes analysis algorithm for DC traction power supply system with PWM rectifier.

• 전력전자학회논문지
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• 제16권5호
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• pp.457-465
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• 2011

본 논문에서는 3상 다이오드 정류기의 고장에 따른 해석 및 고장 판별 기법을 제안한다. 입력전원이나 다이오드소자에 고장이 발생하게 되면 출력 직류단 전압에 큰 맥동을 유발하며 이는 인버터 시스템의 제어 성능을 저하시킬 뿐만 아니라 커패시터의 수명 단축을 야기한다. 본 논문에서는 입력측의 지락 사고 및 다이오드 개방 사고 시의 직류단 전압 특성을 분석하고, 계통주파수의 6배에 주파수마다 측정된 직류단의 순시전압을 직류단 평균 전압과 비교함으로서 고장의 유무 및 종류를 판별하는 알고리즘을 제안하였다. 제안한 알고리즘은 직류단 전압 센서만을 이용하므로 구현이 간단하고 고장 진단을 위한 추가적인 하드웨어가 요구되지 않는다. 실험과 시뮬레이션을 통해 제안한 고장 진단 알고리즘의 타당성을 검증하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2004년도 전력전자학술대회 논문집(2)
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• pp.551-555
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• 2004

The two-transformer full bridge (TTFB) PWM converter has two transformers which act as the output inductor as well as the main transformer, i.e. as the forward and the flyback transformer. Although the doubled leakage inductor of the TTFB makes it easier to achieve the zero-voltage switching (ZVS) of the lagging leg switch along the wide load range, it instigates a serious voltage ringing in the secondary rectifier diodes, which would require the dissipative snubber circuit, cause the serious power dissipation, and increase the voltage stress across those diodes. To overcome these problems, a, new lossless diode-clamp rectifier (LDCR) is employed as the output rectifier, which helps the voltage across rectifier diodes to be clamped on a half the output voltage $(V_o/2)$ or the output voltage $(V_o)$. Therefore, no dissipative snubber for rectifier diodes is needed and a high efficiency as well as low noise output voltage can be realized. The operations, analysis and design consideration of proposed converter are presented in this paper. To verify the validity of the proposed converter, experimental results from a 425W, 385-170Vdc prototype for the plasma display panel (PDP) sustaining power module (PSPM) are presented.

• 전력전자학회논문지
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• 제26권3호
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• pp.237-240
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• 2021

This research proposes a new rectifier circuit to reduce the circulating current of a phase-shifted full bridge converter. The proposed circuit is a structure in which the output inductor of the secondary rectifier circuit is changed to a coupled inductor in the phase-shifted full bridge with the existing center-tapped rectifier. The parts are rearranged after adding a diode. After applying the proposed circuit, the circulating current to the primary current of the transformer and the voltage stress of the rectifier diode on the secondary side of the transformer are reduced. Accordingly, the snubber loss of the rectifier is improved. By reducing the circulating current and snubber loss, the circuit achieves higher efficiency than conventional circuits. In this research, we present the structure of the proposed circuit, its strengths, and the analysis results from experiments. Furthermore, its effectiveness is verified through the experimental results of a prototype converter with an input of 300-400 V and an output of 50 V/1 kW.

• Journal of Power Electronics
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• 제9권6호
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• pp.903-910
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• 2009

In this paper, a digital average current mode control using diode current sensing technique is proposed. Although the conventional inductor current sensing technique is widely used, the sensed signal of the current is negative. As a result, it requires an additional circuit to be applied to general digital controller ICs. The proposed diode current sensing method not only minimizes the peripheral circuit around the digital IC but also consumes less power to sense current information than the inductor current sensing method. The feasibility of the proposed technique is verified by experiments using a 500W power factor correction (PFC) boost rectifier.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.201-204
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• 2007

This paper proposes a improvement of switching converter's input wave form using VIENNA Rectifier(three-phase three-switch three-level PWM Rectifier). VIENNA Rectifier is based on the combination of a three-phase diode bridge and dc/dc boost converter. It can be available to get sinusoidal mains current, and low-blocking voltage stress on rower transistors. In addition, it can control output voltage.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 A
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• pp.395-399
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• 1996

The Clamp Mode(CM) Forward Zero Voltage Switching Multi Resonant Converter(ZVS-MRC) with self-driven synchronous rectifier in studied. The loss at the synchronous rectification stage of the converter is analyzed using MOSFET linear model and is compared with the loss at the conventional schottky diode rectification stage of the converter. From the results of the analysis, it is known that the use of MOSFETs as a synchronous rectifier reduces the loss at the rectification stage over the whole load range comparing the use of schottky diodes as a conventional rectifier in the converter. In order to verify the validity of the analysis, we have built a 33W(3.3V/10A) CM Forward ZVS-MRC with self-driven synchronous rectifier, in which switching frequency is 1MHz, and tested. From the experimental results, it is known that the synchronous rectification achieved about 1W improvement in the loss at the rectification stage and about 3% in the efficiency at the converter as compared with the conventional schottky diode rectification.

• Journal of Power Electronics
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• 제12권4호
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• pp.528-537
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• 2012

This paper presents an interleaved resonant converter with a parallel-series transformer connection in order to achieve ripple current reduction at the output capacitor, zero voltage turn-on for the active switches, zero current turn-off for the rectifier diodes, less voltage stress on the rectifier diodes, and less current stress on the transformer primary windings. The primary windings of the two transformers are connected in parallel in order to share the input current and to reduce the root-mean-square (rms) current on the primary windings. The secondary windings of the two transformers are connected in series in order to ensure that the transformer primary currents are balanced. A full-wave diode rectifier is used at the output side to clamp the voltage stress of the rectifier diode at the output voltage. Two circuit modules are operated with the interleaved PWM scheme so that the input and output ripple currents are reduced. Based on the resonant behavior, all of the active switches are turned on under zero voltage switching (ZVS), and the rectifier diodes are turned off under zero current switching (ZCS) if the operating switching frequency is less than the series resonant frequency. Finally, experiments with a 1kW prototype are described to verify the effectiveness of the proposed converter.

• 한국전기전자재료학회논문지
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• 제29권4호
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• pp.250-254
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• 2016

Currently, power conversion system which converts AC to DC Power is applied in domestic urban railway. The diode rectifier is used in most of them. However the diode rectifier can not control the output voltage and can not regenerate power as well. On the other hand, PWM (pulse width modulation) converter using IGBT (isolated gate bipolar transistor) can control output voltage, allowing it to reduce the output voltage drop. Moreover the Bi-directional conduction regenerates power which does not require additional device for power regeneration control. This paper compared the simulation results for the DC power supply system on both the diode rectifier and the PWM converter. Under the same load condition, simulation circuit for each power supply system was constructed with the PSIM (performance simulation and modeling tool) software. The load condition was set according to the resistance value of the currently operating impedance of light rail line, and the line impedance was set according to the distance of each substations. The train was set using a passive resistor. PI (proportional integral) controller was applied to regulate the output voltage. PSIM simulation was conducted to verify that the PWM Converter was more efficient than the diode rectifier in DC Traction power supply system.