• 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.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.10
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• pp.107-114
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• 2009

Because of the increase of power demand and expansion of downtown, it is necessary to install the power transformers at the substation in the residential area. But the public complaints have increased due to the noise of the power transformers in the substation. A soundproof wall has been employed to the power transformers in the outdoor substations and a soundproof door, a soundproof shutter and soundproof equipment for wind-path has been employed to power transformers in the indoor substations in order to isolate sound propagation from the noise of the power transformers. But the noise reduction results of these methods are not satisfied. In this study, a soundproof enclosure is developed to effectively isolate sound propagation from the noise of the power transformers. The performance of the sound attenuation of the developed soundproof enclosure is verified in a 154[kV] transformer. As a result, 15[dB] sound attenuation in 120[Hz] component is achieved by applying the developed soundproof enclosure to a 154[kV] transformer.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.62 no.4
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• pp.181-185
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• 2013

This paper deals with the electromagnetic loss characteristics of enclosures for a 24kV high voltage switchgear by using a finite element method (FEM). A study on the electromagnetic characteristics of enclosures for a high voltage switchgear should be conducted to minimize the size and the temperature rising of a switchgear. Generally, the enclosures made by stainless steel are used to minimize the eddy current loss caused by the transporting current in Bus bars due to its non-magnetic characteristics although the price of stainless steel is expensive compared with other metal for enclosures. Therefore, a switchgear made by stainless steel enclosures could be fabricated as a small size and are applied to a switchgear in urban substations. On the contrary, the switchgear enclosures made by steel could be fabricated with relatively cheap manufacturing price. However, the temperature easily rises due to the transporting current in Bus bars because steel is a ferromagnetic material. Therefore, the size of a switchgear made by steel enclosures is relatively massive and installed in rural substations. In this paper, the electromagnetic losses in the enclosures of a switchgear according to various enclosure thicknesses are calculated and compared with each other. Especially, we proposed a hybrid type enclosures for a switchgear made by stainless steel (top and bottom enclosure) and steel (left and right enclosure). It is concluded that the cost electromagnetic performance of applying the hybrid type enclosure is favorable to develop a high voltage switchgear.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.36 no.2
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• pp.3-11
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• 2020

The police substation includes work spaces for civil services, interviews, and meetings, etc, and private spaces for rest, showers and cafeterias and so on. Since a large number of rooms for each function should be installed in a relatively small building, it is important to develop an area standard for efficient space organization in consideration of the functional characteristics and usage patterns of each space. The purpose of this study is to suggest the way for improving the area standards for spaces in police substation based on the results of existing standards analysis and case study. For this objective, architectural documents of 161 police substations built after 2013 in Korea were comparatively analyzed. Sixteen of these facilities were selected for field survey and investigated how the workspace and private area were organized and used. The results of investigation showed that there were a number of problematic cases, such as spaces not installed or insufficient, spaces used for two or more functions, spaces installed even though they are not included in the standards. It was mainly due to the fact that several important spaces which had been installed in most police substations were not included in the existing standards. The ways for improvement were suggested like following four points: (1) Modifying the criteria for classifying facility size, (2) Modifying the lists of the required spaces, (3) Specifying the basis of calculation for each space in detail, and (4) Differentiating the way to organize spaces according to the facility size.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.37 no.2
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• pp.175-181
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• 2024

In electrical power substations, bulky iron-core potential transformers (PTs) are installed in a tank of gas-insulated switchgear (GIS) to measure system voltages. This paper proposed a low-power voltage transformer (LPVT) that can replace the conventional iron-core PTs in response to the demand for the digitalization of substations. The prototype LPVT consists of a capacitive voltage divider (CVD) which is embedded in a spacer and an impedance matching circuit using passive components. The CVD was fabricated with a flexible PCB to acquire enough insulation performance and withstand vibration and shock during operation. The performance of the LPVT was evaluated at 80%, 100%, and 120% of the rated voltage (38.1 kV) according to IEC 61869-11. An accuracy correction algorithm based on LabVIEW was applied to correct the voltage ratio and phase error. The corrected voltage ratio and phase error were +0.134% and +0.079 min., respectively, which satisfies the accuracy CL 0.2. In addition, the voltage ratio of LPVT was analyzed in ranges of -40~+40℃, and a temperature correction coefficient was applied to maintain the accuracy CL 0.2. By applying the LPVT proposed in this paper to the same rating GIS, it can be reduced the length per GIS bay by 11%, and the amount of SF6 by 5~7%.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.918-923
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• 2011

On AC railway systems, the neutral sections are installed in front of substations and sectioning posts in order to avoid crash between power that have differing phases. In case railway vehicles pass through these neutral sections, it is necessary for them to switch to coasting driving by notch-off. This may reduce speed of the vehicles, resulting lowered train operation efficiency. The usage of automatic power switching systems makes it possible to pass neutral sections at notch-on, enhancing operation efficiency so that it is appropriate for high-speed railway applications. This paper introduces a simulator that assesses efficiency of automatic power switching systems in neutral sections. The is composed of a power supply system, electric railway vehicles, thyristor switches, and traction motors.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2005-2010
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• 2011

On AC railway systems, the neutral sections are installed in front of substations and sectioning posts in order to avoid crash between power that have differing phases. In case railway vehicles pass through these neutral sections, it is necessary for them to switch to coasting driving by notch-off. This may reduce speed of the vehicles, resulting lowered train operation efficiency. The usage of automatic power switching systems makes it possible to pass neutral sections at notch-on, enhancing operation efficiency so that it is appropriate for high-speed railway applications. This paper analyzed inrush current of main transformer that installed on the train while passing through the neutral section using the simulator.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1014-1019
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• 2011

The substation automation is a system to remote-monitor and control electric power flow. And in line with electrification of railway, an interest in electric railway substation automation is increasing. IEC standardized IEC 61850, IEC 61968 and IEC 61970 communication protocol for the telecommunication standardization of the electric power automation industry. The recent SCADA systems in managed electric railway substations are have the problem about the compatibility with the products which fit to the international standard specification afterward. In this paper, the model of electric railway substation automation based on IEC 61850 and IEC 61970 is presented. And the method supporting the compatibility between the equipment is proposed.

• Journal of Environmental Impact Assessment
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• v.14 no.4
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• pp.195-202
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• 2005

The health risks from the magnetic fields exposure have been brought out difficulties in the construction of transformer substation. According to several epidemiologic studies and the relevant international organizations, magnetic fields should not exceed the exposure limits of 3mG for the people living near electric power lines. The rigid regulation of the exposure levels for the elementary school and residental areas has been established already in Switzerland and Italy. Since 1998, the environmental impact assessment system in Korea has been reviewed for power-frequency magnetic field by precautionary policies. In this study, the possible application of Prior Environmental Performance Review System for the transformer substation was reviewed from the points of the properties of the powerfrequency magnetic fields. The ranges and survey methods of the assessment for the transformer substation were proposed. The ranges of magnetic fields was between 300m to 500m for the 345kV transformer substation. It is necessary to develop further specific assessment methods for various high-voltage transformer substations.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.12
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• pp.2392-2396
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• 2011

This paper deals with the power integration of large urban railway systems to improve regenerative energy utilization. Current regenerative energy utilization is low because there is no special plan for using this energy. If the railway system is integrated with other railway systems, the efficiency is expected to be improved. Through the case studies, to find the realistic effect of integrated operation, real system for the Seoul Metro lines, especially line 5 and 7, had been applied.