• 전력전자학회논문지
• /
• 제20권6호
• /
• pp.566-572
• /
• 2015

This study introduces an LCC resonant converter operating on a continuous conduction mode. The LCC resonant converter has the advantage of improving system efficiency, especially under the rated load condition, because it can reduce conduction loss by improving the resonance current shape and switching loss by increasing the lossless snubber capacitance. The proposed LCC resonant converter is applied to various applications, including a 60 kW EV fast charger, a 24 kJ/s high-voltage capacitor charger, and a 20 kV, 20 kW high-precision DC power supply. Experimental results prove that the proposed LCC resonant converter topology can be effectively used as a converter topology for these applications.

• 조명전기설비학회논문지
• /
• 제28권11호
• /
• pp.84-92
• /
• 2014

In this paper, we propose a three-phase isolated electrolytic capacitorless charger available for quick charger. In the proposed charger, electrolytic capacitor in DC link is eliminated by direct conversion from AC input to DC output. Conventional chargers are two stage structure including AC-DC and DC-DC converters, but the proposed charger can be simplified into single stage converter by using a matrix converter. And the waveform of input currents is improved by giving the weighting factor to the duty ratio of auxiliary switches. In order to verify the effectiveness of the proposed charger, simulations are carried out and a 1.2kW charger was constructed and experimented.

• 한국정보통신학회:학술대회논문집
• /
• 한국정보통신학회 2015년도 추계학술대회
• /
• pp.484-487
• /
• 2015

본 논문에서는 진동에너지와 빛에너지를 이용한 MPPT 기능을 갖는 이중 입력 충전기 회로를 제안한다. 빛에너지는 photovoltaic cell로부터 수확하고, 진동에너지는 piezoelectric cell로부터 수확하여 각각 커패시터에 저장된다. Charger 블록에 의해 배터리 전압이 승압되며 이때 두 가지 에너지원이 모두 입력으로 사용되어 충전하게 된다. 승압하는 방법은 DC-DC boost converter를 사용하였으며 시간 구간에 따라 하나의 인덕터를 공유하는 방법을 적용하였고, 진동에너지와 빛에너지를 입력으로 사용하는 비율은 8:1로 설계하였다. 제안된 회로는 0.35um CMOS 공정으로 설계하였고 배터리 관리블록에 의해 배터리 커패시터의 충전 상태가 제어되며 최대 3V의 전압까지 충전할 수 있다. 설계된 회로의 최대 효율은 88.56%이며, 칩 면적은 패드를 포함하여 $1230um{\times}1330um$이다.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2017년도 전력전자학술대회
• /
• pp.18-19
• /
• 2017

This paper shows the design of the high voltage capacitor charger which using a modified series parallel resonant converter. The used silicon carbide Metal-Oxide Semiconductor Field Effect Transistor (SiC MOSFET) is proper for the few hundred kHz of high switching frequency to overcome the bulk resonant inductor and snubber capacitors. Furthermore, to increase the amount of the charging current, three phase delta transformer is used as well as the secondary sides are connected in parallel. In this paper, the design procedure of the high voltage capacitor charger is suggested and the output power is verified by the experimental results with the rated resistor load.

• 한국화재소방학회논문지
• /
• 제30권6호
• /
• pp.71-77
• /
• 2016

핸드폰 충전기 내 커패시터의 전해액이 전원 입력단자로 누출되고 PCB 기판에 트래킹이 발생하여 탄화도전로가 형성되는 것을 확인하였다. 트래킹이 발생하는 원인을 구조적으로 분석한 결과, 전원 입력단자와 PCB 기판이 커넥터를 이용하여 직결되는 경우에 발생하였다. 커패시터에서 누출된 전해액이 전원입력단자로 흘러 들어가는 양이 많을수록, 전원입력단자의 플러그 핀 사이에 설치된 격벽의 높이가 낮을수록 트래킹 발생율이 높았다. 이에 따라 충전기 내 트래킹 발생율을 낮추기 위해서는 누출된 전해액이 전원입력단자로 흘러 들어가지 않도록 커패시터에 격벽을 설치하거나, 전원입력단자에 설치된 격벽의 높이를 높일 필요가 있다. 또한, 전원 연결단자와 맞닿아 있는 PCB기판의 형태를 ${\Pi}$로 변경한다면 트래킹 발생율이 더욱 줄어들 것으로 판단된다.

• Journal of Power Electronics
• /
• 제15권1호
• /
• pp.31-38
• /
• 2015

In this paper, a buck-boost type battery charger is developed for charging battery set with a lower voltage. This battery charger is configured by a rectifier circuit, an integrated boost/buck power converter and a switched capacitors circuit. A boost power converter and a buck power converter sharing a common power electronic switch are integrated to form the integrated boost/buck power converter. By controlling the common power electronic switch, the battery charger performs a hybrid constant-current/constant-voltage charging method and gets a high input power factor. Accordingly, both the power circuit and the control circuit of the developed battery charger are simplified. The switched capacitors circuit is applied to be the output of the boost converter and the input of the buck converter. The switched capacitors circuit can change its voltage according to the utility voltage so as to reduce the step-up voltage gain of the boost converter when the utility voltage is small. Hence, the power efficiency of a buck-boost type battery charger can be improved. Moreover, the step-down voltage gain of the buck power converter is reduced to increase the controllable range of the duty ratio for the common power electronic switch. A prototype is developed and tested to verify the performance of the proposed battery charger.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2009년도 제40회 하계학술대회
• /
• pp.1025_1026
• /
• 2009

This paper introduces the test a rapid pulsed power charging system for pulsed power application. The charger is designed based on three-phase series resonant inverter followed by air cooled step-up transformers. It has many advantages of lower weight, small size and high efficiency compared with large bulky traditional pulse power charging system. To apply 150kJ pulsed power system, detail test was carried out at various condition and its results shows 90% efficiency at full load condition. And additional experiments such as short, open, and self discharging during charging status are performed to verify reliable operation at abnormal condition and it was confirmed that developed capacitor charger showed very reliable operation all over the tests.

• Journal of Biosystems Engineering
• /
• 제43권2호
• /
• pp.94-102
• /
• 2018

Purpose: In this study, a maintenance free super-capacitor battery charging system based on the photovoltaic module, to be used in agricultural electric carriers, was developed and its charging characteristics were studied in detail. Methods: At first, the electric carrier system configuration is introduced and the electric control components are presented. The super-capacitor batteries and photovoltaic module used in the experiment are specified. Next, the developed charging system consisting of a constant current / constant voltage Buck converter as the charging device and a super-capacitor cell as a balancing device are initiated. The proposed circuit design, a developed PCB layout of each device and a proportional control to check the current and voltage during the charging process are outlined. An experiment was carried out using a developed prototype to clarify the effectiveness of the proposed system. A power analyzer was used to measure the current and voltage during charging to evaluate the efficiency of the energy storage device. Finally, the conclusions of this research are presented. Results: The experimental results show that the proposed system successfully controls the charging current and balances the battery voltage. The maximum voltage of the super-capacitor battery obtained by using the proposed battery charger is 16.2 V, and the maximum charging current is 20 A. It was found that the charging time was less than an hour through the duty ratio of 95% or more. Conclusions: The developed battery charging system was successfully implemented on the agricultural electric carriers.

• 전력전자학회논문지
• /
• 제15권3호
• /
• pp.188-198
• /
• 2010

최근들어, 전기이중층 커패시터 등의 친환경 전력저장장치의 수요가 증가하면서, 이를 위한 양방향 충/방전기의 수요 또한 증가하고 있다. 그러나, 기존의 상용화된 아날로그 제어기를 사용하는 DC-DC 컨버터를 충 방전기로 사용하게 되면, 충/방전 레퍼런스를 제공하는 상위 디지털 제어기와 별도로 아날로그 제어기를 제작해야 하는 문제가 있고, 회로가 복잡해지며, 모드전환 시 과도응답이 좋지 않다. 이에 대한 대안으로 단일 디지털 제어기를 사용하게 되면 쉽게 구현 가능한 설계방식을 이용하여 양방향 시스템의 성능을 향상 시킬 수 있다. 본 논문에서는 단일 회로 단 양방향 벅-부스트 컨버터에 전기이중층 콘덴서를 이용한 친환경 전력저장장치의 양방향 충/방전 시스템을 구현하고, DSP(TI사 TMS320F28335)를 이용한 디지털 제어기를 적용하였다. MATLAB simulink를 이용하여 모의실험을 수행하였고, 하드웨어를 구성하여 실험한 결과, 모의실험과 마찬가지로 양방향 시스템의 응답특성이 개선되었음을 보여주었다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2008년도 제39회 하계학술대회
• /
• pp.988-989
• /
• 2008

This paper describes a rapid pulsed power charging system for pulsed power application. It is capable of charging 35kJ/s energy up to 0.47uF 25kV within 3ms and maximum pulse repetition rate of 300 pps can be achieved. The charger is designed based on three-phase series resonant inverter followed by air cooled set-up transformers thus it has many advantages of lower weight, small size and high efficiency compared with large bulky traditional pulse charger system. Detail design procedure of resonant inverter and high voltage transformers is explained. Experimental results carried out at different condition and its results shows 90% efficiency at full load condition.