• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 춘계학술대회 논문집 전력기술부문
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• pp.201-205
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• 2001

This paper presents the load modeling process and bus load models for KEPCO power system. At first, load devices commonly used in KEPCO power systems were selected, and tested for measuring the voltage and frequency sensitivity of active and reactive power. From this test, about 40 voltage and frequency dependent load models have been obtained. The bus load composition rate for KEPCO power system has been determined using the various recent surveys and papers in order to develop the load model for a power system bus. To verify the accuracy of developed bus load models, the field test for measuring active and reactive power according to artificial variation of the bus voltage was performed at 8 substations for spring summer, autumn, winter cases. With data of this seasonal field test, more reliable bus load models for KEPCO power systems were developed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 C
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• pp.1152-1154
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• 1999

Recently. due to the drastic development of communication method between substations for pilot protective relaying system. The power line carrier(PLC) application is getting obsolete. Consequently, the coupling capacitor voltage transformer (CCVT) loses its necessity for the carrier coupling function, and so wound voltage transformer(VT) can be used to substitute CCVT for voltage signal. However, VT has been reported to give rise to ferro-resonance phenomena, so sufficient consideration on applying the VT to line side is required. This study introduces probable technical problems in using the VT on T/L side, and carries out feasibility study on the basis of modeling results by EMTP(Electro-magnetic transient program)

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 C
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• pp.1478-1480
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• 1999

The accurate analysis of power system requires detailed load model. There are two basic approaches in modeling the load characteristics. One is to directly measure the voltage and frequency sensitivity of the load P and Q at substations and feeders. The other is to build up a composite load model from each load component. Each of these methods has advantages and disadvantages. This paper presents load composition for KEPCO's power system to develop load models by the component-based load modeling.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.111-111
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• 2010

The mold transformers have been widely used in underground substations in large building and have some advantages in comparison to oil-transformer, that is low fire risk, excellent environmental compatibility, compact size and high reliability. In addition, the application of mold transformer for outdoor is possible due to development of epoxy resin. The mold transformer generally has cooling duct between low voltage coil and high voltage coil. A mold transformer made by one body molding method has been developed for small size and low loss, but it needs some cooling method because heat radiation between each winding is difficult. In this paper, the temperature distribution and thermal stress analysis of H class 100kVA pole cast resin transformer for power distribution are investigated by FEM program.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.116-116
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• 2010

This paper introduces an comprehensive monitoring and management program for implementation of a real-time monitoring system that monitors condition of urban railway AC/DC transformers, disconnecting switches, circuit breakers, regulators, and GIS (Gas Insulated Switchgear). Especially, the system is applied to diagnose the overall condition of urban railway substations by sending acquired data through an OPC server to a database, effectively storing and monitoring conditions simultaneously. The above system is a management based system and is also applicable to small-scale systems.

• 한국전기전자재료학회논문지
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• 제23권4호
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• pp.333-337
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• 2010

This paper introduces an overall system design of a real-time monitoring system that monitors condition of urban railway AC/DC transformers, disconnecting switches, circuit breakers, regulators, and GIS (gas insulated switchgear). For effective diagnosis of urban railway facilities we developed optimized sensors and application technology. The proposed system is combined with wireless technology, implementing remote real-time monitoring of urban railway facilities. The derived real-time monitoring system for power facilities in urban railway substations will be applied not only to diagnose low voltage DC (direct current) railways but also to diagnose design of small power facilities of skyscrapers and apartments.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 D
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• pp.2254-2256
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• 2004

Korea Water Resources Corporation (KOWACO), the only organization specialized in water resources management in Korea, is planning to establish a centralized control system for a related operation. in the central control room, of decision making as to water management and electric power generation. This plan is intended to convert the existing on-site operation system in each multi-purpose dam across the nation into a central operation system in the Corporations head office, for which Generation Integrated Operating System (GIOS) will be established control center in the Corporations head office and modernized nine (9) power stations. substations (RDAC). This article discusses realization of GTOS, especially real-time operation of hydropower plants and a specific architectural features for system communication.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1999년도 제14차 학술회의논문집
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• pp.157-160
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• 1999

A prediction method of conditional event matching pre-diction (EMP) for a purpose of predicting nonlinear phenomena of insulator pollution was proposed in this paper. The EMP was used if the conditional probability for increase of insulator pollution exceeded a threshold value. A performance of the EMP was strongly related to selection of database of events and a closeness function. By use of the prediction of the insulator pollution based on the conditional EMP, reliable decision making for the washing timing of the polluted insulators was e-valuated based on actual data in Kasatsu substation, Japan.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.1878-1884
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• 2010

Currently in Korea, neutral sections in front of substations and sectioning posts are greatly divided into AC/DC sections and AC/AC sections. Considering catenary damage and safety issues trains pass crossover by coasting driving at notch-off. However in cases of Japan, China, or Taiwan, the usage of automatic crossover system makes it possible to pass at notch-on, enhancing high-speed railway operation for efficiency, and stability. These are the purposes of developing automatic power crossover system in neutral sections. This paper introduces two methods to detect the position of a train required to activate automatic crossover systems in neutral sections. The optimal method is expected in terms of the distance of neutral section.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.1505-1510
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• 2007

In this paper, the power simulation is used for the prediction of regenerative energy and examination of install location of regenerative inverter for DC railway system. The power simulation was composed to train performance simulation(TPS) and power flow simulation. We performed the power simulation for Seoul subway line 5 and 7, calculation of regenerative energy and examination of substations where regenerative inverter is installed.