• 전력전자학회:학술대회논문집
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• 전력전자학회 2002년도 추계학술대회 논문집
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• pp.103-107
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• 2002

A contact-less power supply system (CPS) allows electrical energy to supply to mobile consumers without any electrical or mechanical contact. CPS works in the same principle as a transformer, with the track litz cable forming the primary circuit and the pickup as the secondary. The track power supply generates the high frequency alternating current in the track cable. The captured AC magnetic field generated by the track conductors produces electrical energy in the pickup coil and the pickup rectifier converts the high frequency AC power to DC while regulating the power to the load. This paper presents the theoretical analysis, simulation and experiment리 results of the series-parallel resonant converter working as contact-less power supply system.

• 전력전자학회논문지
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• 제4권6호
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• pp.507-514
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• 1999

한국전력에서는 인천화력 4호기 수명연장의 일환으로 여자시스템 교체가 이루어졌다. 기존의 회전형 여자 시스템은 발전기축에 부여자기와 교류여자기가 부착되어 회전하는 형태로 과거 스위칭소자 용량의 한계를 극복하기 위하여 설계된 시스템으로 전력연구원에는 회전형 여자시스템을 새롭게 개발된 아날로그와 디지털의 하이브리드 제어기와 대용량 사이리스터 제어정류기를 가지고 잇는 정지형 이중화 여자시스템으로 교체하였다. 설비의 신뢰성을 높이기 위하여 정지형 여자시스템의 상태를 순시 감시하기 위한 데이터 취득 시스템이 설치 되었고 위상제어정류기는 운전시 1대가 고장이 발생하더라도 발전기의 전부하 능력을 유지하기 위하여 3대가 병렬로 운전되는 N+1 방식을 채택하였다. 시스템의 신뢰성 시험은 성능평가를 위한 시운전시에 검증되었으며 성공적으로 운전중에 있다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2014년도 전력전자학술대회 논문집
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• pp.89-90
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• 2014

Recently, one of the switching rectifiers, Power Factor Correction Circuit is often applied in rectification stage to get high efficient conversion of AC-DC SMPS However, it becomes important to select optimal semiconductor switch as well as to design optimal rectifier for achieving higher power conversion. We performed experiments with MOSFET, SiC and GaN FET that are widely used in 600 W Interleaved CRM PFC and include the data in this report. The results are presented for discrete semiconductor and integrated implementations of interleaved CRM PFC.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.1398-1400
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• 2005

In this paper, a modular dc-to-dc converter, in order to apply to the control board of train vehicles, is presented. Forward converter with active-clamp reset circuit and synchronous rectifier(SR) is employed to achieve high efficiency. To reduce the size and height of the converter, low profile magnetic components are used. The design and performance of the modular dc-to-dc converter with experiments on a 50W(5V/10A) prototype for the 60V$\sim$140V input voltage range are presented.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2016년도 추계학술대회 논문집
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• pp.13-14
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• 2016

This paper has introduces a novel Integrated On-board Charger (IOBC) to reduce the size, weight and cost of power conversion stages in Electric Vehicles (EVs). The IOBC is composed of an OBC and a low voltage dc-dc converter (LDC). The IOBC includes a bidirectional ac-dc converter and a bidirectional full-bridge converter with an active clamp circuit. The LDC converter is a hybrid topology combining an active clamped full-bridge converter and a forward converter derived from the Weinburg converter topology. Unlike conventional OBC, the proposed IOBC is compact and the LDC converter of it can achieve a higher efficiency. In addition, the LDC converter of the proposed IOBC can achieve high step-down voltage conversion ratio, no circulating current, no reverse recovery current of the rectifier diodes and small ripple current of output inductor on the auxiliary battery. A 1kW hardware of the LDC converter is implemented to verify the performances of the proposed IOBC.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2019년도 전력전자학술대회
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• pp.159-161
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• 2019

현재 단조용 유도가열 전원으로 사용되는 전류원 SCR 정류기 / 인버터는 입력단의 낮은 역률과 높은 THd를 갖는다. 이러한 단점들 때문에 최근 유도가열 전원장치로써 IGBT PWM 전류원 정류기 및 인버터회로가 연구되고 있다. 본 논문에서는 IGBT PWM 정류기 및 인버터의 제어회로를 제안하고 제어회로의 모델링을 통해 제어기를 설계하여 실험을 통해 그 성능을 검증하였다.

• 전기학회논문지
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• 제57권10호
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• pp.1782-1789
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• 2008

This paper presents the design of acoustic resonance(AR) free and dimmable electronic ballast for 1kW Metal-Halide Lamp(MHL). The proposed Ballast consists of a Full-Bridge(FB) rectifier, a passive power factor correction(PFC) circuit, a full-bridge inverter, an ignitor using LC resonance and a control circuit for frequency modulation and dimming control. Whereas a passive PFC provides advantages in terms of high reliability and low cost for constructing the circuit, it is difficult to supply a stable voltage because of the output voltage ripple that occurs with a period of 120Hz. Although the ballast can be designed with a small size and a light weight if it is driven at a switching frequency between 1 and 100 kHz, AR will occur if the eigenvalue frequency of the lamp coincides with the inverter's operation frequency. The operation frequency was modulated in real time according to the output voltage ripple to compensate for the variation in power supplied to the lamp and eliminate AR. For dimming, the method, which modulated drive frequency of FB inverter using the control of DC level by microprocessor, was used. The Dimming ranged at least from 600W to 1kw as rated power of the lamp with 4 stages. Performance of the proposed technique was validated through numerical analysis, computer simulation using Pspice and by applying it to an electronic ballast for a prototype 1kW MHL.

• 전기학회논문지
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• 제62권9호
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• pp.1313-1317
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• 2013

With increasing demand of power, the equipment of power system is enlarging and the absolute capacity is going up. As a result, when a fault occurs, the fault current is consistently increasing. Therefore, I suggested some solution for limiting the fault current more efficiently. This study shows the characteristics of superconducting limiting elements and normal conducting elements combined with a transformer. We performed a short-circuit test about the fault current by using SCR switching control system operated from a CT. When short circuit accidents happened in the secondary side of a transformer, fault currents flowed and a SCR switching control system was operated. It resulted in a decrease of the fault current in the limited elements of third winding connected in parallel. For this test, we used YBCO thin films and normal conducting elements as the limited elements. Within a cycle, a superconducting fault current limiter with YBCO thin films reduced more than 90% of fault current because the resistance of superconducting elements sustainedly grew. On the other hand, the limiter with normal conductors limited as much as a set value because its resistance characteristic was linear. Consequently, in case of the limiter with superconductor, limiting range of the circuit was wide but the range of protective detection was undefined. In contrast, as for the limiter with normal conductors, limiting range and protection duty were appropriate.

• 대한전자공학회논문지SD
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• 제38권3호
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• pp.211-219
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• 2001

본 논문에서는 RFID를 위한 읽기 전용 CMOS 트랜스폰더를 one-chip으로 설계하였다. 리더에서 공급되는 자기장으로부터 트랜스폰더 칩의 전원을 공급하기 위한 전파정류기를 NMOS 트랜지스터를 사용하여 설계하였으며, 데이터 저장 소자로는 64비트의 ROM을 사용하였다. 메모리에 저장되어 있는 ID 코드는 Manchester 코딩되어 front-end 임피던스 변조 방식으로 리더에 전송된다. 임피던스 변조를 위한 감폭회로로는 리더와 트랜스폰더 사이의 거리가 변해도 일정한 감폭율을 갖는 새로운 감폭회로를 사용하였다. 설계된 회로는 0.65㎛ 2-poly, 2-metal CMOS 공정을 사용하여 IC로 제작되었다. 칩 면적은 0.9㎜×0.4㎜이다. 측정 결과 설계된 트랜스폰더 IC는 인식거리 내에서 약 20∼25%의 일정한 감폭율을 보이며, 125㎑의 RF에 대해 3.9kbps의 데이터 전송속도를 보인다. 트랜스폰더 칩의 전력소모는 읽기 모드시 약 100㎼이다. 인식거리는 약 7㎝이다.

• 전기학회논문지
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• 제62권6호
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• pp.798-802
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• 2013

In a conventional DC power supply used for CO2 laser, the circuit elements such as a rectifier bridge, a current-limiting resistor, a high voltage switch, energy storage capacitors ans a high-voltage isolation transformer using high turn ratio are necessary. Consequently, those supplies are expensive and require a large space. Thus, laser resonator and power supply should be optimally designed. In this paper, we propose a new power supply using high frequency resonance phenomena for CW(Continuous wave) CO2 laser (maximum output of 23W with discharge length of 450mm). It consists of a transformer including leakage inductance, magnetizing inductance and half-bridge converter, a three-stage Cockcroft-Walton and PFC(Power factor correction) circuit. The output ripple voltage can be controlled the minimum of 0.24% under the high frequency switching of 231kHz. Furthermore, the output efficiency was improved to 16.4% and the laser output stability of about 5.6% was obtained in this laser system.