• Proceedings of the KIEE Conference
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.28_29
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• 2009

전력계통의 비접지 계통에 지락 고장이 발생하면 중성점 이동으로 고장이 발생하지 않은 건전상의 전위가 상승한다는 사실은 누구나 다 알고 있다. 이는 전기적으로 균형을 이루고 있는 계통에 지락 고장으로 상간 불균형이 초래되기 때문인데 보통 비접지 계통의 보호는 1상 지락 시는 고장전류가 거의 없기 때문에 영상 과전압을 이용한 한시 보호계전 방식으로, 2중 접지 시는 과전류 계전방식으로 보호 하고 있다. 그런데 고장전류가 없어 상대적으로 파급이 적을 것 같은 1상 지락고장 시 건전 상에 발생한 과전압이 또 다른 고장을 유발, 더 큰 고장으로 진전되어 많은 복구비용을 발생하게 하거나 예상치 못한 현상을 일으켜 고장원인을 분석하고 처리하는데 어려움을 초래하기도 한다. 본 논문은 발전소 비접지 계통에서 발생하는 중성점이동 현상에 대해서 논하고자 한다.

• Proceedings of the KIEE Conference
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.369_370
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• 2009

This paper describes the fault location method for HVDC submarine cables. Most conventional fault location methods can be applied in off-line. However, in this paper, on-line fault location algorithm is proposed using multi-scale correlating of wavelet coefficient and travelling wave. The propagation velocity is measured by field test on Jeju-Heanam submarine cable section. Finally, the fault location algorithm is tested by same system modeling using EMTP/ATP.

• The Transactions of The Korean Institute of Electrical Engineers
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• 제56권4호
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• pp.641-644
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• 2007

The electro-mechanical mercury relay is used as an auxiliary relay of power facility because it is superior to operating time and no-bounce. So the KEPCO had used the mercury relay for operating HVDC(High Voltage Direct Current) system. But it has many problems with facility operation by occurrence of mercury evaporation, held contact point and malfunction according to long term use, furthermore it is forbidden to produce for fear of environmental pollution in 2002. This paper presents the no-mercury relay development, comparison test and application.

• The Transactions of the Korean Institute of Electrical Engineers
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• 제35권5호
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• pp.193-198
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• 1986

In this paper, 1-168 hours ahead load prediction algorithm is developed for power system economic weekly operation. Total load is composed of three components, which are base load, week load and weather-sensitive load. Base load and week load are predicted by moving average and exponential smoothing method, respectively. The days of moving average and smoothing constant are optimally determined. Weather-sensitive load is modeled by linear form. The paramiters of weather load model are estimated by exponentially weighted recursive least square method. The load prediction of special day is very tedious, difficult and remains many problems which should be improved. Test results are given for the day of different types using the actual load data of KEPCO.

• Proceedings of the KIEE Conference
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• 대한전기학회 2000년도 하계학술대회 논문집 A
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• pp.495-497
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• 2000

The KEPCO is developing the load forecasting sysetm using land use simulation method and distribution planning system. Distribution planning needs the data of presents loads, forecasted loads sub-statin, and distribution lines. Using the data, determine the sub-station and feeder lines according to the load forecasting data. This paper presents the method of formulation processfor the long term load forecasting and optimal distribution planning and optimal distribution planning. And describes the case study of long term distribution planning of Kwangju city accord to the newly applied method.

• Proceedings of the KIEE Conference
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• 대한전기학회 2000년도 하계학술대회 논문집 A
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• pp.552-554
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• 2000

This paper presents algorithm to plan construction and expanding of substation considering contingency accidents by proposing utilization factor according to configuration of bank system. In this paper, at first, proper sphere of supply area in each district which could be standardized with respect to its supply capacity is established under assumption which was made long term load forecasting in district respectively. Secondly, goal of utilization ratio according to configuration of substation bank was set to keep reliability by remaining sound bank when it happen to one bank accidents Finally, optimal construction and expanding of substation considering economy and reliability simultaneously about substation to exceed these ratio could be anticipated.

• Proceedings of the KIEE Conference
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• 대한전기학회 2000년도 하계학술대회 논문집 A
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• pp.212-214
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• 2000

The distance relay technique used for transmission line protection operates overreach and underreach to the self protection region because the power system becomes complex and fault conditions are different. To solve these problems, this paper describes new technique to set the reliable self protection lesion. The trip region of the quadrilateral distance relay is set by training of multi layer recurrent elman network. The proposed network is able to reach the trip zone for the fault impedance, fault initial angle and source impedance variance correctly.

• Proceedings of the KIEE Conference
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.123-124
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• 2006

우리나라 전력계통은 비수도권 지역의 발전단가가 수도권 지역의 발전단가보다 값이 싸기 때문에 비수도권에서 수도권지역을 연결해주는 6개의 북상선로에 흐르는 융통조류의 양이 하나의 경제성을 평가하는 기준이 될 수 있다. 본 논문에서는 병렬형 FACTS 투입에 따른 혼잡비용 감소를 융통조류 여유(f-V)해석을 통하여 평가하였다. 수도권 지역에 병렬형 FACTS가 투입된다면 수도권지역에 무효전력 공급으로 인하여 융통조류 증가를 우리나라 중장기 계통에 대해 모의하고, 이때의 발전 비용을 계산하여 FACTS 투입에 따른 혼잡비용의 경감효과를 분석하였다.

• Proceedings of the KIEE Conference
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.480-482
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• 2005

In this paper, utilization of load duration curves is presented for analyzing the effect of load power factor and determining the value of load power factor effectively. In addition, the power factor sensitivity of generation cost and integrated costs including voltage variation penalty cost are used for determining the value of the load power factor from the point of view of voltage regulation and economic investment. It is shown through the application to the KEPCO power system that the load power factor can be enhanced effectively and appropriately using the load duration curve.

• Proceedings of the KIEE Conference
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.149-151
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• 2005

A new approach considering CO2 air pollution constraints in the long-term generation mix is proposed under uncertain circumstances. A characteristic feature of the presented approach in this paper is what effects give the air pollution constraints in long term best generation mix. Best generation mix problem is formulated by linear programming with fuel and construction cost minimization with load growth, reliability (reserve margin rate) and air pollutionconstraints. The proposed method accommodates the operation of pumped-storage generator. It was assumed in this study that the construction planning of the hydro power plants is given separately from the other generation plans. The effectiveness of the proposed approach is demonstrated by applying to the best generation mix problem of KEPCO-system, which contains nuclear, coal, LNG, oil and pumped-storage hydro plant multi-years.