• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.11-12
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• 2014

차량용 양방향 DC/DC 컨버터에 적합한 새로운 토포로지 및 그 구성방법을 제안한다. 제안된 구성방식은 공통접지를 사용하는 새로운 양방향 공진형 충전펌프 토포로지와 기존 양방향 컨버터와 결합한 2단방식의 양방향 DC/DC 컨버터이다. 제안된 2배 승압 공진형 충전펌프는 전력변환 효율 증대와 병렬 구동 시 공진회로가 영향이 받지 않게 하기위해 출력 측으로 전력 전달시 인덕터가 입력전원과 직렬로 구성하게 하였다.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.407-408
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• 2014

최근 하이브리드 자동차, 지능형 자동차 등을 비롯한 미래형 자동차 분야와 관련된 연구 개발과 맞물려 자동차 전장 회로 시스템은 더욱 복잡해지고 있다. 자동차 전장 시스템의 경향으로 그린카를 들 수 있는데 이에 대한 하나의 방향성은 연비 개선과 최적의 운행조건을 위한 ISG System( Idle Stop & Go system )의 채택으로 가고 있는 추세이다. 여러 장점을 가진 ISG 시스템이지만 시동 모드 시 많은 양의 전류가 순간적으로 흘러가 일순간 전압강하 발생과 높은 스위칭 주파수에 의한 표피효과가 일어난다. 이를 제어하는 기술로 전장회로상의 DC/DC 컨버터 기술이 핵심이라 할 수 있다. 이에 따라 본 논문에서는 확장성이 용이한 고효율 DC/DC 컨버터를 제안하고 모의 실험과 실제 실험을 통해 검토한다.

• Journal of Advanced Navigation Technology
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• v.24 no.6
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• pp.566-572
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• 2020

In a wireless power transmitter, the characteristics and effects of wireless power transmission between two induction coils are investigated, and a power converter circuit and a battery charger/discharger circuit using wireless power transmission technology are proposed. The advantage of wireless power transmitters and wireless chargers is that, instead of the existing plug-in-mounted wired charger (OBC; on-board charger), the user can wirelessly charge the battery without connecting the power source when charging power to the battery. There is. In addition, the advantage of wireless charging can bring about an energy efficiency improvement effect by using the secondary side rectifier circuit and the receiving coil, but the large-capacity long-distance wireless charging method has a limitation on the transmission distance, so many studies are currently being conducted. The purpose of the study is to study the transmitter circuit and receiver circuit of a wireless power transmission device using a primary coil, a secondary coil, and a half bridge series resonance converter, which can transmit power of a non-contact type power transmitter. As a result, a new topology was applied to improve the power transmission distance of the wireless charging system, and through an experiment according to each distance, the maximum efficiency (95.8%) was confirmed at an output of 3 kW at an 8 cm transmission distance.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.24 no.2
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• pp.133-138
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• 2024

Lithium-ion batteries are used in many fields due to their high energy density, fast charging conditions, and long cycle life. However, overcharging, over-discharging, physical damage, and use of lithium-ion batteries at high temperatures can reduce battery life and cause damage to people due to fire or explosion due to damage to the protection circuit. In order to reduce the risk of these batteries and improve battery performance, the characteristics of the charging and discharging process must be analyzed and understood. Therefore, in this paper, we analyze the charging and discharging characteristics of lithium-ion batteries using a battery charger and discharger and simulator to reduce the risk of loss of life due to overcharge and overdischarge, as well as casualties from fire and explosion due to damage to the protection circuit.

• The Transactions of the Korean Institute of Power Electronics
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• v.16 no.6
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• pp.587-593
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• 2011

A new high power density and low cost Photovoltaic Power Conditioning System (PV PCS) with energy storage system is proposed. Its high power density and cost effectiveness can be achieved through the unification of the maximum power point tracker and battery charger/discharger. Despite of the reduced power stage, the proposed system can achieve the same performances of maximum power point tracking and battery charging/discharging as the conventional system. Moreover, the high voltage stress across the link-capacitor can be relieved through the series-connected link-capacitor with the battery. Therefore, a large number of series/parallel-connected link-capacitors can be reduced by 4-times. Especially, when the utility power failure happens, both photovoltaic and battery energies can be supplied to the load with only one power stage. Therefore, it features a simpler structure, less mass, lower cost, and fewer devices. Finally, to confirm the operation, validity, and features of the proposed system, theoretical analysis and experimental results from a single phase AC 220Vrms/1.5kW prototype are presented.

• Journal of Electrical Engineering and Technology
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• v.9 no.6
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• pp.2004-2012
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• 2014

Energy storage devices are necessary to obtain stable utilization of renewable energy sources. When black-out occurs, distributed renewable power sources with energy storage devices can operate under standalone mode as uninterruptable power supply. This paper proposes a dynamic response analysis with small-signal modeling for the standalone operation of a photovoltaic power generation system that includes a bidirectional charger/discharger with a battery. Furthermore, it proposes a DC-link voltage controller design of the entire power conditioning system, using the storage current under standalone operation. The purpose of this controller is to guarantee the stable operation of the renewable source and the storage subsystem, with the power conversion of a very efficient bypass-type PCS. This paper presents the operating principle and design guidelines of the proposed scheme, along with performance analysis and simulation. Finally, a hardware prototype of 1-kW power conditioning system with an energy storage device is implemented, for experimental verification of the proposed converter system.

• Journal of Energy Engineering
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• v.2 no.1
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• pp.104-113
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• 1993

Due to steady increase of electric power demand and decrease of load factor, the economic and reasonable operation of electric power system is necessary. Because of this reason, dispersed battery energy storage system(BESS) with fast response is receiving attractive attention. With these considerations, 20 kVA BESS is designed and tested to investigate the possibility of BESS application to power system. This paper describes the design specifications of simulator and test results. BESS is composed of batteries, conversion equipments, interconnecting equipments to power system, and control parts of the system. The inverter of BESS can carry out two functions as charger and discharger. Also, it can operate as a VAR compensator by four quadrant operation. Since this system is designed as a simulator of MW system, the conceptual design of MW system is possible by using the test result of test system The study of BESS is preliminary stage for the future MW class BESS.