• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.1
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• pp.98-104
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• 2004

This paper represents the fast and efficient load transfer guide for fault or outage restoration in distribution system. For restoration guide, system trace is performed to reverse direction(source side) from tie breaker in tree-structured distribution network. Search space and breaker's combinational number for restoration guide are greatly reduced. It is proposed the load transfer method including first stage restoration(single load transfer, double load transfer, triple load transfer), second stage restoration(transferring load to neighboring feeder in order to expand the capacity margin) and load cutoff guide. The proposed method can be easily applied to primary customer restoration, multi-fault recovery and distribution automation system.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.7
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• pp.20-25
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• 2005

In this paper, the short-term load forecasting of transformers is performed by artificial neural networks. Input parameters of the proposed algorithm are peak loads of pole-transformer of previous days and their maximum and minimum temperatures. The proposed algorithm is tested for one of transformers in Seoul, Korea. Test results show that the proposed algorithm improves the accuracy of the load forecasting of transformer compared with the conventional algorithm. The reposed algorithm can help to prevent some damages by over-loads of transformers.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.5
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• pp.118-125
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• 2003

This paper presents a scheme for the placement of dispersed generator systems(DGs) based on load model in unbalanced systems. Groups of each individual load model consist of residential, industrial, commercial, official and agricultural load The main idea of solving fuzzy goal programming is to transform the original objective function and constraints into the equivalent multi-objectives functions with fuzzy sets to evaluate their imprecise nature for the criterion of power loss minimization, the number or total capacity of DGs and the bus voltage deviation, and then solve the problem using genetic algorithm The method proposed is applied to IEEE 13 bus unbalanced distribution systems to demonstrate its effectiveness.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.5
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• pp.95-102
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• 2008

Typical household loads have nonlinear loads including a personal computer, video, refrigerator, microwave oven, TV, and audio set. These nonlinear loads generate harmonic currents and create distortions on the sinusoidal voltage of the power system. Harmonic field measurements have shown that the harmonic contents of a waveform varies with time. A cumulative probablistic approach is the most commonly used method to solve time varying harmonics. This paper provides in depth analysis on harmonics field measurement of the typical household loads for one year period and the survey is conducted with the objectives to identify the trends of harmonic distortion level present and indentify the future trends of metering in the presence of nonsinusoidal current and voltage waveforms in the system.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.6
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• pp.78-83
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• 2004

Currently used DLC(Direct Load Control) algorithm is only focused on ON/OFF load control not concerning about reliving participated customer's inconvenience and load priority. Therefore, that is a major obstacle to attract customer participating in demand response program. To overcome the above defects, the authors represent direct load control algorithm using priority based dynamic programming. the proposed algorithm is that participant customer send E-mail to DLC center about priority of load before executing DLC, then DLC algorithm decide which load to be OFF by using priority and off time constraint of the load. By using dynamic programming based on the order of priority for DLC algorithm it is possible to maximize participating customer's satisfaction and it will help to attract more customer's participating in demand response program.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.14 no.1
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• pp.102-108
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• 2000

This paper presents a result of practical study about the adjustment of load correlation equation for the load management of pole transformer. For adjusting the load correlation equation, we analyze the correlative relation between working electric energy[kWh] and peak load[A]. To enhance the accuracy of correlation equation, we classify the 12 representative area patterns. And then, we select the 24 sample pole transformer for each area pattern. For the reliability of the data using the load correlation equation, load management equipment is utilized for each sample pole transformer. Through the on-line data acquisition, we construct the database. For adjusting the load correlation equation, we consider the two points. One is the goodness of fitness for load correlation equation and the other is prevention of pole transformer damage due to the overload. Finally, we propose the correlation equation using the linear and quadratic equation all at once. Through the case studies, we verify that the proposed load correlation equation is reduced the error ratio than conventional correlation equation.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.2
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• pp.98-103
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• 2002

In case of power demand forecasting, the most important problems are to deal with the load of special-days. Accordingly, this paper presents the method that forecasting long (the Lunar New Year, the Full Moon Festival) and short(the Planting Trees Day, the Memorial Day, etc) special-days peak load using neural networks and regression models. long and short special-days peak load forecast by neural networks models uses pattern conversion ratio and four-order orthogonal polynomials regression models. There are using that special-days peak load data during ten years(1985∼1994). In the result of special-days peak load forecasting, forecasting % error shows good results as about 1 ∼2[%] both neural networks models and four-order orthogonal polynomials regression models. Besides, from the result of analysis of adjusted coefficient of determination and F-test, the significance of the are convinced four-order orthogonal polynomials regression models. When the neural networks models are compared with the four-order orthogonal polynomials regression models at a view of the results of special-days peak load forecasting, the neural networks models which uses pattern conversion ratio are more effective on forecasting long special-days peak load. On the other hand, in case of forecasting short special-days peak load, both are valid.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.5
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• pp.107-115
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• 2006

The existing DLC system functionally has two defects. One is it has to be controlled by operators whenever customer's portion of loads are increased more than predefined objected load. Therefore, it may be possible for propagating uncontrolled loads if operators make a mistake. The other one is that currently used DLC algorithm is usually focused on ON/OFF load control not concerning about reliving participated customer's inconvenience. Therefore, that is a major obstacle to attract customer participating in demand response program. This paper represents direct load control system using active database. By using active database, DLC system can control customer's load effectively without intervening of operator. And by using dynamic programming based on the order of priority for DLC algorithm, it is possible to maximize participating customer's satisfaction.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.4
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• pp.100-106
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• 2008

Typical household load have nonlinear loads including a personal computer, video, refrigerator, microwave oven, TV, and audio set. These nonlinear loads generate harmonic currents and create distortions on the sinusoidal voltage of the power system. Harmonic field measurements have shown that the harmonic contents of a waveform varies with time. A cumulative probablistic approach is the most commonly used method to solve time varying harmonics. This paper provides in depth analysis on harmonics field measurement of the typical household loads and harmonics simulation using EDSA program for the case study.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.8
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• pp.81-86
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• 2007

This paper proposes the scheme to improve the current direct load control(DLC) program by inspecting the problems of the DLC program. In order to increase the number of the customers participating DLC program, a reduction of the base incentive and an increase of the direct load control incentive are suggested based on the interruption cost of electric power considering the characteristics of load types and the introduction of demand side bidding is recommended. Secondly, the standards of power system operations is required to control DLC program efficiently for the penalty, interruption times, the number of interrupting loads, notice time for the load interruption and the periods of the DLC program contract.