• 대한전기학회논문지:전력기술부문A
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• 제49권11호
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• pp.566-574
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• 2000

This paper propose a heuristic algorithm based on the Branch-Exchange (BE) method to solve Optimal feeder Routing(OFR) problem for the distribution system planning. The cost function of the OFR problem is consisted of the investment cost representing the feeder installation and the system operation cost representing the system power loss. We propose a properly designed heuristic strategy, which can handle the horizon-year expansion planning problem of power distribution network. We also used the loop selection method which can define the maximum loss reduction in the network to reduce calculation time, and proposed a new index of power loss which is designed to estimate the power loss reduction in the BE. The proposed index, can be considered with both sides, the low voltage side and voltage side branch connected with tie one. The performances of the proposed algorithms and loss index were shown with 32, 69 example bus system.

• 대한전기학회논문지:전력기술부문A
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• 제52권8호
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• pp.463-470
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• 2003

This paper proposes an expert system, which is able to determine the problem-solving strategy for diversity events occurred on the distribution system. The events include events related to the fault, scheduled outage and optimal operating task such as feeder line fault, line scheduled outage, line overload, system load balancing, system loss minimization, main transformer fault, main transformer scheduled outage, main transformer overload, main transformer protection control. The expert system enhances the reliability of software designed by the integrated concept for the diversity events. The expert system is implemented in C language. And the effectiveness and accuracy for the expert system is verified by simulating the event cases for typical distribution model.

• 대한전기학회논문지:전력기술부문A
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• 제52권3호
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• pp.151-157
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• 2003

Wind farm interconnected with grid can supply the power into a power network not only the normal conditions, but also the fault conditions of distribution network. If the fault happened in the distribution power line with wind fm, the fault current level measured in a relaying point might be lower than that of distribution network without wind turbine generator due to the contribution of wind farm. Consequently, it may be difficult to detect the fault happened in the distribution network connected with wind generator This paper describes the effect of the interconnected wind turbine generators on protective relaying of distribution power lines and detection of the fault occurred in a power line network. Simulation results shows that the current level of fault happened in the power line with wind farm depends on the fault impedance, the fault location. the output of wind farm. and the load condition of distribution network.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 C
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• pp.1213-1216
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• 1998

This paper presents the result of a feasibility study for the prediction method of fault symptoms on 22.9kV distribution line. In this paper, real distribution data was collected and analyzed to isolate failure signatures or parameters which were distinct behaviors before and after failure incident. A new strategy of analysis-based (event-date concept) prediction algorithm for the distribution insulators and a developed model system were also discussed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 C
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• pp.1114-1117
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• 1998

Recent applications of neural networks to power system fault diagnosis have provided positive results and have shown advantages in process speed over conventional approaches. This paper describes the application of neural network to fault detection and classification in distribution lines using the fundamental component, 2-5th harmonics index, even and odd harmonics index, and zero phase current. The Electromagnetic Transients Program (EMTP) is used to obtain fault patterns for the training and testing of neural networks. The proposed fault detection and classification method in distribution lines is obtained by analysing the difference among normal, HIF, ground fault, short circuit fault condition.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 C
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• pp.964-966
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• 1998

The TC curve of recloser which used in KEPCO's distribution line is a little different in a pattern with the TC curve of sub-station OCR. So it sometimes fails in protection coordination. And the recloser sometimes does mis-open/close owing to the inrush current of CB reclosing when a fault occurred on the source-side of the recloser. The mis-open/close is another trouble maker. This Paper Present a new delay TC curve of recloser which has the same pattern with the TC curve of OCR, and a new instantaneous TC curve of recloser which doesn't mal-function to the inrush current. In addition, this paper present another two TC curves for the serial positioning of 2 reclosers. So we accomplished the simple protection coordination of OCR-recloser-fuse.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 C
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• pp.932-934
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• 1998

Electric power distribution feeders are susceptible to faults caused by a variety of situations such as adverse weather conditions, tree contacts, equipment failure, accidents, etc. Distribution circuit faults result in a number of problems related to the reliability of service and customer power quality. In the past, the permanent interruption of customer service resulting from a blown fuse or a recloser lockout was the only factor which was used to determine service reliability. So we developed KODAS(Korea Distribution Automation System) with successful and had fieid-testing of Distribution Automation System in last three years at Kang-dong Branch Office. In performing the project, KEPRI has gained valuable experience, through dealing with many difficult problem. This paper is depicted about the circuit breaker coordination problems in the Underground for the Distribution Automation Feeder.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 A
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• pp.237-240
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• 2003

유도전동기는 기동시 전류가 정격전류의 6배$\sim$8배에 이르기 때문에 경부하로 운전하는 경우에는 역률을 떨어뜨릴뿐만 아니라 과다한 기동전류로 인해 계통전원에 순간전압 강하를 유발시켜 선로의 전력품질(Power Quality) 저하가 심각하게 대두되고 있다. 본 논문에서는 PSCAD/EMTDC 패키지를 이용하여 IEEE에서 제시한 배전 계통 13버스 모형 모델 및 유도기 부하를 모델링하여 사고모의 및 DSTATCOM의 보상 효과를 시뮬레이션을 통하여 보였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 A
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• pp.470-472
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• 2003

This paper presents the measurement results and the statistical analysis of electrical and magnetic fields in the vicinity of overhead distribution lines. The maximum values of electrical and magnetic fields are 0.042kV/m and 8.3mG. The median values are 0.005kV/m and 1.3mG. The electrical and magnetic fields of distribution lines are compared to those of transmission lines and home appliances.

• 전기학회논문지
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• 제60권7호
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• pp.1410-1416
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• 2011

A corrosion detecting system for 22.9 kV distribution power line insulation cable, which can travel autonomously along the live line, is proposed. Eddy current test method is employed to detect the corrosion, and the system developed here is capable of detecting internal corrosion of a ACSR-OC. Somewhat details of the electrical and mechanical mechanism of the system and traveling algorithm are introduced. Experimental results applied to the sample cables having artificial corrosion and the operating distribution lines are provided. From the result, we confirmed that the system is useful for detecting internal corrosion of a ACSR, and is expected to be a new non-destructive testing equipment in the area of diagnosis for the distribution power line.