• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 추계학술대회 논문집 학회본부
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• pp.43-45
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• 1995

In accordance with the development of switching devices, the voltage and current signal have involved the time harmonics. But most power meter is designed to operate in sinusoidal signal. Therefore, this paper evaluate the operating state and characteristic of power meter under the voltage and current included the time harmonics, analysing the results which are obtained by means of theorical analysis and an experiment of several instruments for power measuring.

• 전기학회논문지
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• 제57권5호
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• pp.881-888
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• 2008

We present a novel fault diagnosis methodology using acoustic sensor systems and neural independent component analysis for large-scaled power machines. Acoustic sensors are carried out to measure sounds generated from power machines whose signal is used to determine whether fault is occurred or not. Acoustic measurements are independently mixed and deteriorated from original source signals. We propose a demixing algorithm against such mixed signals by means of independent component analysis which is achieved based on information theory and higher-order statistics to derive learning mechanism.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.179-180
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• 2008

배전선로의 효과적인 운영을 위해 최근 들어 자동검침 데이터를 활용한 부하분석에 대한 연구가 진행되고 있다. 일반적인 부하분석 방식은 자동검침 고객의 데이터를 이용하여 대표 부하패턴을 생성하고 이를 이용하여 미 검침 고객의 부하패턴을 생성하여, 전체 배전선로의 회선 및 구간에 대한 15분/시간/일/주/월 단위의 최대부하 및 부하패턴 등을 분석하는 방법이다. 기존에는 고객을 분류하기 위해 계약종별 코드만을 사용하였으나, 같은 계약종별 코드를 갖는 고객이라 하더라도 부하패턴이 다른 경우가 많아서 부하분석의 정확도를 떨어뜨렸다. 본 연구에서는 고객의 계약종별 코드뿐 아니라 다양한 고객속성 정보와 15분 단위 자동검침 데이터를 이용하여 k-means 기법을 통해 고객을 분류하는 방식을 제안하였다.

• International Journal of Safety
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• 제7권1호
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• pp.21-25
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• 2008

The occurrence of a corona is that electrical discharge due to the heterogeneity that occurs when an electrical field is concentrated in an electrode due to a cusp formed on said electrode. Wire treatment at the end of a 154kV dead end clamp for end users accelerates the occurrence of corona, which in turn leads to power loss and noise. In this study, the characteristics of the corona which occurs between porcelain insulators and support clamps of overhead lines used in l54kV power receiving facilities for end users were investigated. The corona, which cannot be identified by one common method, was measured utilizing a UV image camera. A risk assessment for fire damage and its status was suggested. The stress distribution of the electrical field by length of bare wire was suggested by means of the finite element method (FEMLAB). As a result, it was found to affect a porcelain insulators. These results can be utilized for the enhancement of clamp installation and safety in power facilities.

• Journal of Power Electronics
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• 제2권3호
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• pp.171-180
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• 2002

New 42-volt automotive electrical systems can provide significant improvements in vehicle performance and fuel economy. It is crucial to provide protection against load dump and other overvoltage transients in 42-volt systems. While advanced active control techniques are generally considered capable of providing such protection, the use of passive transient voltage suppression (TVS) devices as a secondary or supplementary protection means can significantly improve design flexibility and reduce system costs. This paper examines the needs and options for passive TVS devices for 42-volt applications. The limitations of the commonly available automotive TVS devices, such as Zener diodes and metal oxide varistors (MOV), are analyzed and reviewed. A new TVS device concept, based on power MOSFET and thin-film polycrystalline silicon back-to-back diode technology, is proposed to provide a better control on the clamp voltage and meet the new 42-volt specification. Both experimental and modeling results are presented. Issues related to the temperature dependence and energy absorbing capability of the new TVS device are discussed in detail. It is concluded that the proposed TVS device provides a cost-effective solution for load dump protection in 42-volt systems.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2006년도 전력전자학술대회 논문집
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• pp.222-224
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• 2006

To improve the drawback of LCMPPT(Limit Cycle Maximum Power Point Tracking) controller of the existing two power conversion stages, an advanced MPPT scheme of single power conversion stage is proposed in this paper. This topology is faster on the control speed by means of current control method and the system configuration is simpler. The Authors produce a battery charger by using a cost effective one-chip processor (PIC16F877A) and evaluate another application on the basis of simulation. As a result, the proposed new LCMPPT algorithm is confirmed to be stable and useful.

• 전력전자학회논문지
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• 제8권5호
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• pp.435-441
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• 2003

순시전압강하보상기 (DVR)는 순시전압강하 및 상승을 보상하기 위한 가장 효과적이고 경제적인 수단으로 알려져 있다. 본 논문은 계통의 전압이 사고에 의해서 심하게 왜곡되는 경우에서도 계통과 동기된 정현적인 기준파를 생성하는 방법을 제시한다. 제안된 기준파발생기 (RWG)는 사고로 왜곡된 전압으로부터 원래의 정현적인 파형을 추출하고 정상 성분만의 전압을 합성하여 DVR의 제어에 사용하도록 한다. 전윈 전압의 사고 순간에도 RWG는 과도적인 문제가 없는 안정된 정현 파형을 출력한다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.178-178
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• 2000

In this paper, intelligent methods using digital protection relay in power management and control system is developed in order to protect power systems by means of timely fault detection during operation and control at starting for induction motor which have various load environments and capacities in power systems. The digital protective relay was designed with DSP CPU(TMS320C31) to Protect and measure more quickly and precisely. The test result on the basis of KEMCl120 and IEC60255, show that the operation time error of the digital motor protection relay is improved within $\pm$5%. Also, we can control motors at starting according to starting types with simple method as programmable sequence editor. So we can improve the demerits of high cost and much manhour for rework.

• 한국산업융합학회 논문집
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• 제4권3호
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• pp.263-266
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• 2001

In this paper, intelligent methods using digital protection relay in power SCADA system is developed in order to protect power systems by means of timely fault detection during operation and control at starting for induction motor which have various load environments and capacities in power systems. The digital protective relay was designed with DSP CPU(TMS320C31) to protect and measure more quickly and precisely. The test result on the basis of KEMC 1120 and IEC60255, show that the operation time error of the digital motor protection relay is improved within ${\pm}5%$. Also, we can control motors at starting according to starting types with simple method as programmable sequence editor. So we can improve the demerits of high cost and much manhour for rework.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 A
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• pp.82-84
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• 1994

This paper presents a design of vertical axis Darrieus wind turbine for wind-power generating system. The wind turbine consists of two troposkien blades, diameter is 10m approximately, and chord length 380mm, tip ratio speed 4. The design of turbine is laid for the main data of rated wind speed 10m/s, turbine speed 78rpm, the generating power is estimated to 25kW, and this is contorted to commercial power line by means of three phase synchronous generator-inverter system.