• The Transactions of the Korean Institute of Power Electronics
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• v.10 no.2
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• pp.203-210
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• 2005

A study on the hybrid micro power source for the IMT2000 application has been presented. The hybrid micro power source is composed of solar cell, super-capacitor and battery. To compensate for the pulse loader of the IMT2000 application, the super-capacitor is connected through the lithium-lon battery to absorb the pulse discharge current. The solar cell provides the additional current to compensate for the depleted current and it is controlled to operate at the maximum power point voltage. A novel maximum power point tracking method is presented to operate at the pulse discharge load conditions and verified to have superior tracking performance through experiment. The controller design for the hybrid micro power source has been presented and verified through experiment.

• The Transactions of the Korean Institute of Power Electronics
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• v.10 no.1
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• pp.70-77
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• 2005

A new converter to transfer energy from a low-voltage AC current source to a battery is proposed. It is focused to find operational modes of the converter. The low-voltage AC current source is an equivalent of the piezoelectric generator, which converts the mechanical energy to the electric energy. The converter consists of a full-bridge MOSFET rectifier and a MOSFET boost converter in order to make the converter small and efficient. The operational principle and modes of the converter are investigated with the consideration of effects of the parasitic capacitances of MOSFETs and diode. The results are proved with simulation studies using PSIM and Pspice.

• The Transactions of the Korean Institute of Power Electronics
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• v.15 no.6
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• pp.441-450
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• 2010

Lithium battery is widely used as the power source of various electronic devices. The formation process which is the repeated charging and discharging process is essential in the production of lithium battery. In this paper, it is proposed and designed the DC-DC converter that can charge and also discharge the lithium battery in one converter. The proposed converter is designed by considering the charge/discharge characteristics of the lithium battery. The converter is operated as a forward converter in charging process and a electrically isolated boost converter in discharging process. Based on the analyses, the number of transformer turns, inductor, capacitor, and switching devices are designed. Finally, the validity of the design for the proposed converter is verified by both simulations and experiments.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.12
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• pp.989-996
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• 2021

In the case of an unmanned aerial vehicle using a battery as a power source, there are restrictions in performing the mission because the battery capacity is limited. To extend the mission capability, it is important to minimize battery usage while the flight to the mission area. In addition, by using the battery usage prediction model, the possibility of mission completeness can be determined and it can be a criterion for selecting an emergent landing point in the mission planning stage. In this paper, we propose a battery usage prediction model considering as one of the environmental factors in the three-dimensional space. The required power is calculated according to the flight geometry of an unmanned aerial vehicle. True battery usage which is predicted from the required power is verified through the comparison with the battery usage prediction model. The optimal flight trajectory that minimizes battery usage is produced and compared with the shortest travel distance.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.419-422
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• 1999

This paper deals with stand-alone Photovoltaic system(SPVS) with charger/discharge controller. Main power source of SPVS are generally solar cel and battery. Therefore SPVS can be classified into variable types in accordance with connection type between battery and solar cell. SPVS with charger/discharge controller which can operate solar cell a maximum power point is suggested and designed with instantaneous controller. And system operating characteristics are verified by experiment with a laboratory prototype in this paper.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.1074-1076
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• 2000

This Paper reports on an experimental and theoretical work about self exited Half-Bridge inverter for contact less battery chargers. The steady state characteristics of inverter are analysis and the experimental result for 500kHz, universal AC source input have been obtained. These inverter is suitable for the portable appliances with battery chargers such as cellular phone.

• Proceedings of the KIPE Conference
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• 1996.06a
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• pp.103-108
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• 1996

In this paper, a novel utility connected photovoltaic power generation system with unity power factor and uninterruptable power system facility and its control strategy are proposed. The proposed photovoltaic(PV) system is connected in parallel between utility and load. The PV system provides an uninterruptable voltage to load, a maximum power tracking to solar array, and power factor correction to the utility. The proposed system has the following advantages compared with the conventional utility connected PV system. 1. Harmonic elimination Function 2. Feeding the photovoltaic energy to the utility 3. Providing the uninterruptible power source along battery to the load In case that the photovoltaic array system is on the poor power generation, the battery and capacitor of the PV system are charged by three phase utility source and the inverter in the PV system only provides the reactive current to eliminate the harmonic current exited on the utility. In the normal operation mode, the PV system supplies active power to load and reactive power to utility in order to maintain the unity power factor and to regulate ac load voltage.

• Proceedings of the KIEE Conference
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• 2001.04a
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• pp.222-226
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• 2001

본 논문에서는 단상 H-bridge 구조의 VSC (Voltage Source Converter)를 이용하여 계통전원을 사용하는 부하의 고조파 전류 보상기능과 전원 Back-up 기능을 갖는 부하전력보상기를 보여준다. 이 두 제어 기능은 전원전압의 유무에 따라 APF의 컨버터 동작과 UPS의 인버터로 동작하게 함으로써 기존 UPS에 부하 전류의 고조파 보상이라는 부가적인 이득을 갖는 이중전력보상기(Dual Function Power Compensator)라 할 수 있다. 컨버터 제어는 Battery 충전 동작과 APF 동작을 동시에 수행하며, 인버터 제어는 정전시 부하에 전원을 공급하는 UPS로서의 동작을 수행하게 된다. 두가지 동작이 성공적으로 수행되기 위해서는 1. 전원전압의 신속한 검출과 판단, 2. 컨버터의 Battery 충전, 3. APF동작을 위한 부하전류의 고조파 전류계산, 4. 전원전압의 동기추종 등이 각각의 동작모드별로 순조롭게 연계동작 되어 야 한다. 본 논문에서는 DFPC의 발생배경과 제안된 DFPC 제어모드의 구분을 결정하는 전원전압의 검출방법에 대하여 소개한다. 그리고 제안된 DFPC의 실제 시스템을 제작하여 각각의 동작상황과 성능을 시험하여 그 결과를 보여준다.

• Journal of Electrical Engineering and Technology
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• v.12 no.6
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• pp.2138-2145
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• 2017

A hybrid system combining renewable technologies with diesel generators is a promising solution for rural electrification. Myanmar has many renewable energy resources, and many regions that cannot be supplied with electricity from the main grid. Therefore, in this study, we select a village in Myanmar, which is located far away from the substation, and evaluate the economic feasibility of a hybrid system for the village considering the specific local conditions and resource availability. We consider a hybrid system composed of a photovoltaic source, diesel generator, battery energy storage system, and converter. The load profiles of the household data from the village, and the solar radiation profiles are determined. The advantages of the hybrid system, in terms of cost, reliability, and environmental effects are analyzed through simulations using commercial software. The simulation results show that, for the selected village in Myanmar, a hybrid system with battery energy storage can reduce the cost and greenhouse gas emissions while maintaining reliability. We also obtain an optimized design in terms of the component size for the selected hybrid system with battery energy storage.

• Journal of the Korean Institute of Gas
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• v.14 no.3
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• pp.14-20
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• 2010

This paper was studied on the explosion hazard by spark discharge of the lithium-ion battery. The experimental samples were chosen lithium-ion battery(general, notebook) which were used for source of portable equipment. The IEC(International Electrotechnical Commission) type spark ignition test apparatus and experimental gases such as methane, propane, ethylene or hydrogen were used for explosiveness test. It was confirmed through the experiment that the explosion hazard by spark discharge. Also, it was used thermal imager for confirm that spontaneous ignition possibility by short-circuit. As the result, this paper verified that lithium-ion battery should be used and designed by special attention safety in the hazardous zone which is existed explosiveness gas.