• Proceedings of the KIEE Conference
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• summer
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• pp.85-87
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• 2004

Supervisory control and data acquisition (SCADA) systems are essential parts of power system which employ a wide range of computers and communication technologies. The traditional SCADA system is mainly for information exchange in only one company, and the information is provided only to the operator or administrator. But in the deregulated environment, we need much more information, which can be exchanged among different companies. With the rapid development of internet, we can use it to access information easily. This paper proposes web technologies to be applied in power system in order to display some important information through accessing data from database, and to realize the real time control of the substation. The functions of SCADA system will be implemented by a set of Web-based components. The monitoring and control of standard 154[kV] substation model is already realized in the laboratory test. The Web-based SCADA system is able to provide sufficient information and control for pow or system through an efficient and economical way.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.192-193
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• 2006

An AC electrical railroad system has rapidly changing dynamic single-phase load, and at a feeding substation, three-phase electric power is transformed to the paired directional single-phase electric power. There is a great difference in electrical phenomenon between the load of AC electrical railroad system and that of general power system. Electric characteristics of AC electrical railroad's trainload are changed continuously according to the traction, operating characteristic, operating schedule, track slope, etc. Because of the long feeding distance of the dynamic trainload, power quality problems such as voltage drop, voltage imbalance and harmonic distortion may also occur to AC electrical railroad system. These problems affect not only power system stability. but also power quality deterioration in AC electrical railroad system. The dynamic simulation model of AC electrical railroad system presented by PSCAD/EMTDC is modeled in this paper, and then, it is analyzed voltage drop and power quality for AC electrical railroad system both with single-Phase distributed STATCOM(Static Synchronous Compensator) installed at SP(Sectioning Post) and without.

• Proceedings of the KIEE Conference
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• 2003.07e
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• pp.110-112
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• 2003

Harmonics happened due to nonlinear systems such as UPS, SCR controlled motors, and fluorescent lighting in distribute power system is very important subject to optimal operate and control of power system. Harmonics sometimes takes place incorrect operation of protective relaying system under normal condition on power system. This paper presents the actual recording data of transformer located at substation of industrial installation for harmonic analysis in detail.

• Proceedings of the KIEE Conference
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• 1997.07c
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• pp.954-957
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• 1997

In this paper, we analyze the voltage sag caused by reclosing on electric power distribution system. When a fault is on the electric system, a reclosing operation brings a voltage sag on the feeders which is supplied with a common substation transformer. By analyzing the fault wave-form measured in the field, it is showed that a voltage sag is in proportion to a fault current. Also, we propose an adaptive reclosing scheme. This scheme changes the number of reclosing as a function of the magnitude of a fault voltage and the fault type. As the proposed scheme is compared with conventional scheme in the side of voltage sag and permanent fault, it is verified that the proposed scheme is more effective than conventional scheme.

• Journal of Electrical Engineering and Technology
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• v.3 no.1
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• pp.20-28
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• 2008

This paper proposes a method for solving distribution system planning problems taking into account demand uncertainty and geographical information. The proposed method can automatically select appropriate location and size of a substation, routing of feeders, and appropriate sizes of conductors while satisfying constraints, e.g. voltage drop and thermal limit. The demand uncertainty representing load growth is modeled by fuzzy numbers. Feeder routing is determined with consideration of existing infrastructure, e.g. streets and canals. The method integrates planner's experience and process optimization to achieve an appropriate practical solution. The proposed method has been tested with an actual distribution system, from which the results indicate that it can provide satisfactory plans.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.5
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• pp.2279-2284
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• 2011

In most of radial distribution systems, the overcurrent protection coordination is adopted for the protection of apparatus and the improvement of electrical power system reliability. The protection coordination structure in distribution substation is composed of several circuit breakers(CB) with distribution lines originating from one substation bus under one transformer, which trip for their fault current. But sufficient analysis is necessary for the capacity of CB's in distribution systems with several distribution generations(DG). In this paper, a protection coordination method not to exceed the traditional capacity of CB's was proposed and certified through simulation by the PSCAD-EMTDC S/W.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.10a
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• pp.371-374
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• 2008

KEPRI has carried out IEC61850 communication conformance test about the IED trial products. This paper describes dataset conformance testing, one of the IEC 61850-10 conformance test items, and test procedures on IED. KEPRI plans to construct the testing field of IEC 61850 based substation automation system with domestic IEDs confirmed their IEC 61850 communication service including dataset.

• Proceedings of the KIEE Conference
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• 2001.11b
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• pp.26-28
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• 2001

This paper discussed for harmonic analysis of 154kv system in Kwangyang steel works. The harmonic modelings are developed by harmonic measurement for scores of days in a 154kv substation at a same time. In this paper, the measurement values of harmonic are compared to the analysis results in incoming line. Case studies are presented to predict harmonic distortion of the future system.

• Proceedings of the KIEE Conference
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• summer
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• pp.199-201
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• 2004

KEPCO, has been made a lot of efforts for computerization for distribution planning system since 1980's, And as a results, DISPLAN (Distribution PLANning System) for systematic and effective planning was developed in 2003 and is being used for feeder and substation planning of KEPCO branch office. In this paper the distribution load forecasting algorithm in DISPLAN is represented and the application was showed.

• Journal of Electrical Engineering and Technology
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• v.13 no.2
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• pp.669-676
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• 2018

Transmission system has been well studied since long time and power system techniques of distribution system are more or less derived from transmission system. However, unlike transmission systems, many practical issues are encountered in the distribution system. Considerable amount of error is observed in voltage obtained from the Feeder Remote Terminal Units (FRTUs) measured by the pole mounted PTs along the distribution feeder. Load uncertainty is also an issue in distribution system. Further, penetration of Distributed Generators (DGs) creates voltage variations in the system. Hybrid radial/ loop distribution system also make it complicated to handle distribution system. How these constraints to be handled under Distribution Automation (DAS) environment in order to obtain error free voltage is described in this paper and therefore, a new approach of voltage error correction technique has been proposed. The proposed technique utilizes reliable data from substation and the FRTUs installed in DAS. The proposed technique adopts an iterative process for voltage error correction. It has been tested and proved accurate not only for conventional radial systems but also for loop distribution systems.