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ABSTRACT: An approach is often used to estimate the reliability value to determine consumer's economic losses resulting from service interruptions. The quantitative estimation of interruption costs are important and meaningful work. Further the restructuring of the electric industries worldwide, most of the electric utilities and consumers have to consider the two important elements such as supply reliability and quality while calculating the related costs and the contract to sell or purchase electricity because it takes costs to keep the two elements at their higher level. Especially, the interruption or the supply reliability will have the influence on the bilateral contract between the suppliers and customers as a key point to determine the price of electric power in the competitive electric market. The increasing use of electrical and electronic machines day-by-day the electrical power supply system and the environment on the process of generation to consumption of electricity also are being changed. In other words both suppliers and consumers of electricity are required to be responsible for their interruption costs since the monetary losses are resulted from the service interruptions. This paper addresses the analysis of interruption costs and the studies made through the direct interview with Korean industrial customers for the period of two years. It is conducted to evaluate the direct and short duration interruption costs resulting from local random electrical supply interruptions. The cost is evaluated by providing a designed questionnaire focused on the experience or the preparative actions which consumers predicted they would take. In the first phase, authors made a survey on all types of industry with 176 industrial customers and evaluated them as per standard industry classification (SIC). In that case, the evaluation data obtained are not so reasonable, because the number of sampled industries was small and the sampled industries were surveyed by being divided-
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into 18 types. So, in the second phase the authors concentrated on only 4 types of 302 industries who have many and large sensitive loads to the short duration interruption
Transmission and Distribution Conference and Exhibition, 2005/2006 IEEE PES; 06/2006
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ABSTRACT: This paper analyzes the present status of power quality and outlines the development of a monitoring system of power quality based on the experience of a series of authors' researches and field measurements for industrial customers in Korea. It also proposes the functions of the monitoring device and the efficient analysis method based on the Korean electrical act and international quality standards. Finally, the authors suggest some countermeasures for advancing the power quality to cope with the competitive electric power market and customers' needs after restructuring of electric power industry according to KEPCO (Korea Electric Power Corporation)'s plan, which is to be completely separated by distribution system in near future in Korea.
Power System Technology, 2004. PowerCon 2004. 2004 International Conference on; 12/2004
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ABSTRACT: Concrete poles with steel reenforcing are mostly used as KEPCO's overhead distribution line poles. The reenforcing should be of rod or wire and the thickness of concrete cover can be thin as 9 mm. The exposed reenforcing on the pole top which should be sealed with mortar or concrete by rule, does not touch the metallic supporter for overhead ground wire normally, however, as the bottom treatment is not prescribed, exposed reenforcing will easily constitute electrical contact with earth when erected for normal use. Under normal operations, concrete pole will do nothing electrically as seen above, and concrete poles are usually treated as insulated things even when insulation coordination is studied. In this study, current flowing through pole itself, while comparatively small impulsive current flow through the ground lead by injecting current impulses to overhead ground wire, were found experimentally.
Power System Technology, 2004. PowerCon 2004. 2004 International Conference on; 12/2004
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ABSTRACT: This paper presents the results of direct interview survey of Korean industrial customers conducted to evaluate the direct, short-term impacts and costs resulting from local random electrical supply interruptions. The cost is evaluated using the questionnaires authors designed, which are mainly on the experience or preparatory actions consumers predicted they would take. Economic evaluation of reliability that traditionally takes into account duration and frequency of interruption does not accurately reflect the lost value or economic impacts of industrial customer, especially large size, caused by any kind of interruption. So, to imply the substantial difference in costs incurred by different customer group, the authors apply the international standards, i.e. IEC, IEEE, of the recent classification of interruption to reflect the difference of interruption characteristics on the questionnaires for the analysis of the interruption cost.
Power System Technology, 2004. PowerCon 2004. 2004 International Conference on; 12/2004
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ABSTRACT: In good conditioned laboratory, measurement of impulse voltage and current was not so complicate. But in field or real scale outdoor demonstrated overhead lines, it is not so easy, because induced high voltage shock to ground connection of instrument, distributed measuring device like HV divider and others. Also control of impulse current generator is one of the problems to get like a standard waveform. Most of all, the hardest problem is economical limitation. To get a economical measuring system, in the middle of concrete pole near to bottom but separate from ground plane, a measuring system combined with normal digital oscilloscope and ups with backup battery were installed using double shielded metallic box. And HV dividers and Rogowski coils installed and connected to oscilloscope through a hole of double shield box. And three measuring points were connected with normal control cable for connection of serial communication system. Communication structure were combined several RS485 modules and main desktop computer. To avoid HV shock from impulse current, simple switching circuit was assembled with control relays. With simple communication program and manual synchronized switching action, the measuring system was well done but data transfer speed was limited at 9600. The advantage of this measuring system is economic aspect and can be operated only 1 person minimum. This system was make good result in field condition with real scale demonstration system.
Power System Technology, 2004. PowerCon 2004. 2004 International Conference on; 12/2004
