• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.670-672
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• 2005

발전원이 다른 계동으로 연계된 춘천, 남춘천변전소의 태전선로간 Loop 시행시 일부배전선로가 Trip되는 현상에 대하여 PSSE 검토 TOOL을 활용하여 계통을 모의하고 변압기 병렬운전조건에 대한 물리적 의미와 검토대상 배전선로 계통특성, 주변 발전원의 발전력과의 상관관계를 기술검토를 통하여 계통특성을 분석함으로써 Loop시행이 가능한 계통여건을 파악, 선로 운영의 최적방안을 제시하고자 한다.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.65 no.4
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• pp.235-241
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• 2016

Grid-connected, large-capacity energy storage systems (ESS) can be used for peak load supply, frequency regulation, and renewable energy output smoothing. In order to confirm the capability of battery ESS to provide such services, 4MW/ 8MWh battery ESS demonstration facility was built in the Jocheon substation on Jeju Island. The frequency regulation technology developed for the Jocheon demonstration facility then became the basis for the 28MW and 24MW frequency regulation ESS facilities installed in 2014 at the Seo-Anseong and Shin-Yongin substations, respectively. The operation control systems at these two facilities were continuously improved, and their successful commercialization led to the construction of additional ESS facilities all over Korea in 2015. In seven (7) locations nationwide (e.g., Shin-Gimje and Shin-Gyeryeong), a total of 184 MW of ESS had been commercialized in 2016. The trial run for the new ESS facilities had been completed between April and May in 2016. In this paper, results of the trial run from each of the ESS facilities are presented. The results obtained from the Seo-Anseong and Shin-Yongin substations during a transient event by a nuclear power plant trip are also presented in this paper. The results show that the frequency regulation battery ESS facilities were able to quickly respond to the transient event and trial run of ESS is necessary before it is commercialized.

• KEPCO Journal on Electric Power and Energy
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• v.2 no.2
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• pp.227-232
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• 2016

To test the effectiveness of using an energy storage system for frequency regulation, the Energy New Business Laboratory at KEPCO Research Institute installed a 4 MW energy storage system (ESS) demonstration facility at the Jocheon Substation on Jeju Island. And after the successful completion of demonstration operations, a total of 52 MW ESS for frequency regulation was installed in Seo-Anseong (28 MW, governor-free control) and in Shin-Yongin (24 MW, automatic generation control). The control system used in these two sites was based on the control system developed for the 4 MW ESS demonstration facility. KEPCO recently finished the construction of 184 MW ESS for frequency regulation in 8 locations, (e.g. Shin-Gimjae substation, Shin-Gaeryong substation, etc.) and they are currently being tested for automatic operation. KEPCO plans to construct additional ESS facilities (up to a total of about 500 MW for frequency regulation by 2017), thus, various operational tests would first have to be conducted. The high-speed characteristic of ESS can negatively impact the power system in case the 500 MW ESS is not properly operated. At this stage we need to verify how effectively the 500 MW ESS can regulate frequency. In this paper, the effect of using ESS for frequency regulation on the power system of Korea was studied. Simulations were conducted to determine the effect of using a 524 MW ESS for frequency regulation. Models of the power grid and the ESS were developed to verify the performance of the operation system and its control system. When a high capacity power plant is tripped, a 24 MW ESS supplies power automatically and 4 units of 125MW ESS supply power manually. This study only focuses on transient state analysis. It was verified that 500 MW ESS can regulate system frequency faster and more effectively than conventional power plants. Also, it was verified that time-delayed high speed operations of multiple ESS facilities do not negatively impact power system operations. It is recommended that further testing be conducted for a fleet of multiple ESSs with different capacities distributed over multiple substations (e.g. 16, 24, 28, and 48 MW ESS distributed across 20 substations) because each ESS measures frequency individually. The operation of one ESS facility will differ from the other ESSs within the fleet, and may negatively impact the performance of the others. The following are also recommended: (a) studies wherein all ESSs should be operated in automatic mode; (b) studies on the improvement of individual ESS control; and (c) studies on the reapportionment of all ESS energies within the fleet.

• Proceedings of the KOSOMBE Conference
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• v.1995 no.05
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• pp.179-182
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• 1995

Although air, water, and noise pollutions have been widely recognized, electromagnetic forces(EMF) hazard has been rarely recognized as a pollution and very little studies has been done in this country. Thus, in this study electromagnetic forces radiated by various home appliances, once machines, and communication equipments were measured and so were several places radiating strong EMF such as subway stations and electric substations. Among the home appliances microwave oven senates lots of magnetic field and microwaves, and electric mattress does strong magnetic field. In video game room strong magnetic and considerable electric fields were measured. It was observed strong magnetic field inside of electric powered train and very strong magnetic and electric fields on some platforms. Hand-phone and car-phone radiate very hazardous level of microwaves to brain and that they rapidly come into wide use. In this study data base for various electric machines and places radiating strong EMFs were constructed and could be used for future epidemiological studies.

• Proceedings of the KIEE Conference
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• 2007.04b
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• pp.152-154
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• 2007

This paper represents the criteria of earthing system for substation design in Korea. The construction of new substations and expansion of existing facilities are commonplace projects in KEPCO(Korea Electric Power Corporation). The KEPCO has had the only design criteria, which need to be adequate criteria considering the new technology and environment in Korea.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10a
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• pp.678-682
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• 1988

Current substation SCADA system has only one control center where two or three operaters monitor and control more than 40 substations spreaded far and wide. The scope of this system is too wide to cope with the concurrent multiple accidents in electric network by the typhoon and large mow. This paper describes the method to organize the optimal structure of substation SCADA system using remote console and small scale control center.

• Proceedings of the KIEE Conference
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• 2004.05b
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• pp.220-222
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• 2004

The IEC standards related to the Technical Regulation in Korea Electricity Business Act are classified into the standards/guides for electrical system and the specifications for electrical equipment/materials. IEC Standard 60364 "Electrical Installations of Buildings" and IEC Standard 61936 "Power Installations Exceeding 1 kV AC" prepared by IEC Technical Committee(TC) 64 and TC 99 respectively, are representative standards for electrical installations of buildings, substations, industrial plants, etc.

• Journal of Electrical Engineering and Technology
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• v.13 no.2
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• pp.540-549
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• 2018

This paper proposes the method of active distribution network expansion planning considering distributed generation integration and distribution network reconfiguration. The distribution network reconfiguration is taken as the expansion planning alternative with zero investment cost of the branches. During the process of the reconfiguration in expansion planning, all the branches are taken as the alternative branches. The objective is to minimize the total costs of the distribution network in the planning period. The expansion alternatives such as active management, new lines, new substations, substation expansion and Distributed Generation (DG) installation are considered. Distribution network reconfiguration is a complex mixed-integer nonlinear programming problem, with integration of DGs and active managements, the active distribution network expansion planning considering distribution network reconfiguration becomes much more complex. This paper converts the dual-level expansion model to Second-Order Cone Programming (SOCP) model, which can be solved with commercial solver GUROBI. The proposed model and method are tested on the modified IEEE 33-bus system and Portugal 54-bus system.

• KEPCO Journal on Electric Power and Energy
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• v.8 no.2
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• pp.119-126
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• 2022

A growing number of gas-insulated transformers in underground power substations in urban areas are approaching 20 years of operation, the time when failures begin to occur. It is thus essential to prevent failure through accurate condition diagnosis of the given facility. Various solid insulation materials exist inside of the transformers, and the generated decomposition gas may differ for each gas-insulated equipment. In this study, a simulation system was designed to analyze the deterioration characteristics of SF₆ decomposition gas and insulation materials under the conditions of partial discharge and thermal fault for diagnosis of gas-insulated transformers. Degradation characteristics of the insulation materials was determined using an automatic viscometer and FT-IR. The analysis results showed that the pattern of decomposition gas generation under partial discharge and thermal fault was different. In particular, acetaldehyde was detected under a thermal fault in all types of insulation, but not under partial discharge or an arc condition. In addition, in the case of insulation materials, deterioration of the insulation itself rapidly progressed as the experimental temperature increased. It was confirmed that it was possible to diagnose the internal discharge or thermal fault occurrence of the transformer through the ratio and type of decomposition gas generated in the gas-insulated transformer.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1110-1111
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• 2007

These days, the concerns about maintenance and repair of electric facilities for stable and reliable electric power supply are increasing day by day. Because, we can have enormous damages economically and socially from a problem of the facilities, no matter how it is a small one. Especially, electric facilities in our country had been built abruptly from 40 years ago, so it can be thought that here are great amount of old facilities that must be repaired or replaced with new one, and the number would be increased time by time. On this situation, many researchers are studying the efficient and reliable method of maintenance for electric facilities and the results are applied on the facilities gradually by growing interests of operators and managers of the facilities. In this paper, the IED(Intelligent Electronic Devices) for Diagnosis system of electric machines are described. It takes analog data from a sensing device and operates digital processor to get a optimum digital data for diagnosis system. Now, this device is applied on several high voltage substations to diagnose and maintain GIS. Brief schematic of total diagnosis system and the construction of the IED are included in this paper.