• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.224-225
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• 2006

In this paper, the design of Power supply for high power magnetron system is stuied. For magnetron drive, three kinds of power supply is required for main high voltage, magnet and heating filament. Detail design was accomplished with basic simulation and real system is developing based on basic design.

• Journal of Power Electronics
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• 제18권2호
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• pp.383-394
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• 2018

This paper presents an isolated power factor correction converter for general-purpose electric vehicle chargers with a wide output voltage range. The converter is based on an asymmetrical dual active bridge structure so that the voltage stress of switching devices can be eliminated by transferring the transformer leakage inductance to the circuit parameters. Harmonic and output controls are performed by secondary switches, and primary switches are only operated at a fixed frequency with a 50% duty ratio. A harmonic modulation technique is also adopted to obtain a near-unity power factor without input current monitoring. The feasibility of the proposed charger is verified with a 3.3 kW prototype.

• Journal of Power Electronics
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• 제14권3호
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• pp.458-467
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• 2014

In this paper, a single-phase current-source bidirectional converter topology for V2G applications is proposed. The proposed converter consists of a single-phase current-source rectifier (SCSR) and an auxiliary switching network (ASN). It offers bidirectional power flow between the battery and the grid in the buck or boost mode and expands the output voltage range, so that it can be compatible with different voltage levels. The topology structure and operating principles of the proposed converter are analyzed in detail. An indirect control algorithm is used to realize the charging and discharging of the battery. Finally, the semiconductor losses and system efficiency are analyzed. Simulation and experimental results demonstrate the validity and effectiveness of the proposed topology.

• Journal of Electrical Engineering and Technology
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• 제9권1호
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• pp.143-153
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• 2014

This paper presents a novel application of LCC resonant converter for 60kW EV fast charger and describes development of the high efficiency 60kW EV fast charger. The proposed converter has the advantage of improving the system efficiency especially at the rated load condition because it can reduce the conduction loss by improving the resonance current shape as well as the switching loss by increasing lossless snubber capacitance. Additionally, the simple gate driver circuit suitable for proposed topology is designed. Distinctive features of the proposed converter were analyzed depending on the operation modes and detail design procedure of the 10kW EV fast charger converter module using proposed converter topology were described. The proposed converter and the gate driver were identified through PSpice simulation. The 60kW EV fast charger which generates output voltage ranges from 50V to 500V and maximum 150A of output currents using six parallel operated 10kW converter modules were designed and implemented. Using 60kW fast charger, the charging experiments for three types of high-capacity batteries were performed which have a different charging voltage and current. From the simulation and experimental results, it is verified that the proposed converter topology can be effectively used as main converter topology for EV fast charger.

• 전기학회논문지
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• 제63권9호
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• pp.1212-1218
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• 2014

For OBC (On-Board Charger) and LDC (Low DC-DC Converter) used as essential power conversion systems of PHEV (Plug-in Hybrid Electric Vehicle), system performance is required as well as reliability, which is need to protect the vehicle and driver from various faults. While current development processor is sufficient for embodying functions and verifying performance in normal state during development of prototypes for OBC and LDC, there is no clear method of verification for various fault situations that occur in abnormal state and for securing stability of vehicle base, unless verification is performed by mounting on an actual vehicle. In this paper, a CCM (Charger Converter Module) was developed as an integrated structure of OBC and LDC. In addition, diverse fault situations that can occur in vehicles are simulated by a simulator to artificially inject into power conversion system and to test whether it operates properly. Also, HILS (Hardware-in-the-Loop Simulation) is carried out to verify whether LDC is operated properly under power environment of an actual vehicle.

• 한국전자파학회논문지
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• 제27권1호
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• pp.84-87
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• 2016

본 논문에서는 자기공명 방식의 무선전력전송 시스템용 100 W급 수신기를 설계, 제작하였다. 제안된 수신기는 1.8 MHz 대역, 100 W급 full-bridge 다이오드 정류기와 정전류 충전기로 구성되어 있다. 특히 정류기에는 30 V 이상의 과전압으로부터 수신기를 보호하는 과전압 보호회로와 수신기에 입력되는 여분 전력을 자동으로 소모하여 수신기의 임력임피던스를 부하변동에 관계없이 일정하게 유지시키는 능동 더미 부하가 내장되어 있다. 정전류 충전기는 최대 1 A의 충전 전류로 배터리를 충전할 수 있도록 설계, 제작되었으며, 충전전류를 제어할 수 있도록 구성되었다. 구성된 수신기를 이용하여 자기공명방식 무선충전 시스템을 구성하였다. 시스템은 130 W 송신기, 1.8 MHz 대역 송수신 공진기, 그리고 제안된 수신기로 구성되어 있으며, 자기공명방식으로 48 V 리튬-이온 배터리를 충전하도록 설계되었다. 시스템 측정 결과, 30 cm의 전송거리에서 약 54 %의 시스템 효율을 나타내었다.

• Journal of Electrical Engineering and Technology
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• 제8권4호
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• pp.920-929
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• 2013

Within the project 'e performance' supported by the German Ministry of Education and Research (BMBF) an electric vehicle, powered by two lithium-ion battery packs of different capacity and voltage has been developed. The required Energy Management System (EMS) in this system controls the current flows of both packs independently by means of two individual dc-dc converters. It acts as an intermediary between energy storage (battery management systems-BMS) and the drivetrain controller on the vehicle control unit (VCU) as well as the on-board charger. This paper describes the most important tasks of the EMS and its interfaces to the BMS and the VCU. To validate the algorithms before integrating them into the vehicle prototype, a detailed Matlab / Simulink-model was created in the project. Test procedures and results from the simulation as well as experiences and comparisons from the real car are presented at the end.

• 전력전자학회논문지
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• 제19권1호
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• pp.15-22
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• 2014

Recently, parallel operation of dc-dc converters has been widely used in distributed power systems. In this paper, a control method to achieve parallel operation of three-phase bi-directional isolated interleaved dc-dc converters is discussed for the battery charging and discharging system which consists of the 32 battery charger/dischargers and two three-phase bi-directional isolated interleaved dc-dc converters. In the boost mode, the battery energy is delivered to the grid, whereas the grid energy is transferred to the battery in the buck mode operation. The average current sharing control method is employed to obtain an equal conducting of each phase current in the three-phase dc-dc converter. By using the proposed method, the imbalance factor is gratefully reduced from 8 percent to 1 percent. Two 2.5kW three-phase bi-directional dc-dc converter prototype have been built and the proposed method has been verified through experiments.

• 조명전기설비학회논문지
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• 제12권4호
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• pp.100-105
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• 1998

본 논문은 고조파와 무효전력을 보상하는 전력용 능동펼터의 성능을 가지는 무정전 전원장치의 제어기볍올 제안 한다. 제안된 시스템은 단지 하나의 전력변환회로만올 가지고 AC/DC 정류기 및 배터리 충전기 그리고 인버터로서 동작할 수 있다. 더욱이 상용전원이 정상일 경우 제안된 시스템은 비선형 부하에 의해 발생된 고조파 및 무효 전 력올 보상하기 위해 전력용 능동필터 모드로 동작한다. 그리고 상용전원이 비정상일 경우는 인버터로 동작하여 배터리에 충전된 전력을 부하로 공급하는 배터리 방전전력 모드로 동작올 한다. 전력용 능동필터 모드에서 보상전류 를 정확히 계산하기 위한 새로운 폐-루프 방식을 제안한다. 마지막으로 제안된 5[kVA]급 시스템의 성능이 시뮬레이션과 실험결과들에 의해 입증된다.

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