• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.10
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• pp.1412-1419
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• 2012

In this paper, we propose the protection coordination algorithm using communication methode based on IEC 61850. The communication protocol in power distribution management system has been issued by IEC standard, IEC61850 of them, which was made for substation automation system, has researched to apply into power distribution system, even though the standard is not a suitable for the system. In smart distribution management system' launched in 2009, the communication network based on the ethernet network for IEC 61850 has been designed to apply the self-healing concept, which is to perform the system protection through the communication between remote terminal units(RTU) according to the standard. However, it is first time to apply the scheme in the real. Thus, this paper proposed the protection algorithm and consideration for applying communication method and introduced the result of demonstration.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.2
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• pp.325-330
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• 2018

In this paper, we investigated the impedance method for searching fault detection point in case of an accident in the AC electric railway AT feeding system. For this purpose, simulation circuit modeling and prototype hardware are made based on the known numerical analysis. As a result of simulation modeling of the feeding system based on the numerical analysis of the impedance method confirmed that the modeling was properly implemented with an average error rate of 0.07%. Also, as a result of fault event by hardware simulator, it was confirmed that the breaker operation time is shortened and the fault current is decreased while the voltage is close to the supply voltage in the transient state as the point of the fault accident moves away from the substation(SS).

• Proceedings of the KIEE Conference
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• 2005.05b
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• pp.51-53
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• 2005

Grounding systems are responsible rot the safe operation of a power system whetehr power system fault occures or not, their performance guarantees equipmet protection and personnel safety by limited the ground potential rise and touch voltages as well as step voltages under ground fault condition. therefore, it is necessary to measure the ground resistance frequently for checing the performance of grounding system. In order to verigy the designed grounding measurement system feasibility, two comparison verifications, which are the ground resistnace measurements using the designed system on power service and off power service, are carried out for the same substation.

• Proceedings of the KIEE Conference
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• 2008.10a
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• pp.95-96
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• 2008

We constructed an on-line PD monitoring system for the 380kV U/G Cable project at the Riyad 9012 substation in Saudi-arabia. The system will be monitoring the termination of the two 380kV XLPE Cables to prevent unexpected failure of the cable insulation. The system had been tested in the laboratory and on-site for detection of various PD signals and reliability of operation. The system distinguish the existence and nonexistence of the partial discharge and then judge the source of partial discharge using automatic PD pattern recognition software.

• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.116-118
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• 2000

The modern power system including lots of measuring devices and controller is large and complex total information system. A Lot of data and system information are transmitted to operators, and analysing these information and system management is very important. Recently, GUI(Graphic Users Interface) is emphasized as a method that operators carry out their duties, effectively. In this paper. a simulator that can show state estimation and detection of bad measuring devices is introduced for domestic 154kV/22.9kV distribution substations. C language and Visual Basic is used for this simulator. and TCP/IP is adopted to consider connection with a Power system.

• Proceedings of the KIEE Conference
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• 2001.05a
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• pp.266-269
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• 2001

컴퓨터 기술과 통신. 네트워크 기술의 발달로 전력설비의 보호방식은 단순한 보호 기능 외에 전체 시스템을 자동으로 보호. 제어하는 추세로 발전하게 되었다. 이러한 새로운 보호개념을 구축하기 위해서는 디지털형 보호계전기와 이를 네트워크로 엮는 통신 기술, 데이터를 취득 가공. 관리하는 데이터 처리 기술이 필수적이다. 본 논문에서는 변전소 자동화 시스템에 필수적인 디지털 보호계전기의 개발 사례와 변전소 자동화 시스템의 네트워크 구성 및 데이터처리 방법을 소개하고 있다.

• Proceedings of the KIEE Conference
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• 2001.05a
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• pp.319-321
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• 2001

When the fault occurred at distribution system, the restoration was late. There are 2 reasons The one is the error of fault location the other is multiple possible candidates of fault location. This paper presents two of new techniques for diagnosing fault regions. The proposed diagnosis scheme is capable of accurately identifying the location of fault upon its occurrence. based on the integration of information available from protective devices and measured load current change at the substation. In this paper expert system for real fault region is presented using these facts. Testing of the developed system using EMTP Simulation Model has demonstrated.

• Proceedings of the KIEE Conference
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• summer
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• pp.73-75
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• 2004

This paper presents the ability and the application of software packages for distribution planning which are DISPLAN(Distribution Planning System) and DLPLAN(Distribution Line Planning System) developed in KEPCO. After calculating size and position of maximum load by administration section for distribution, it forecasts the demand of distribution load considering growth location, increment, new load plan, etc of load by annual. Also it calculates distribution loss, voltage drop using modeled distribution line by you, and support for establishment and enlargement plan of substation and distribution line, decision of most optimal path. And it presents the abstract of used algorithm to develop this system.

• KEPCO Journal on Electric Power and Energy
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• v.4 no.2
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• pp.107-114
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• 2018

In recent years, ESS (Energy Storage System) has been widely used in various parts of a power system. Especially, due to its fast response time and high ramp rate, ESS is known to play an important role in regulating grid frequency and providing rotational inertia. As the number of installed and commercially operating ESSs increases, the reliability becomes an important issue. This paper introduces control schemes and presents its test method for grid-connected ESS for primary frequency regulation. The test method allows to verify the control operation in the individual operation mode and state. A validation of the method through actual ESS test in a electrical substation is presented in the case study section.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.6
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• pp.1108-1114
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• 2016

The cause of failure in the AT feeding system is divided into grounding, short-circuit of feeding circuit and internal faults of the railway substation. Since the fault current is very high, real-time current is detected and the failure must be immediately removed. In this paper, a new DC offset elimination filter that can remove component to decrease in the form of exponential function using low-pass filter was proposed in order to extract the fundamental wave from distorted fault current. In order to confirm the performance of the proposed filter method, AT feeder system was modelled by simulation tool and simulations were performed under various conditions such as fault location, fault resistance and fault voltage phase angle in case of trolley-rail short-circuit fault. When applying the proposed DC-offset removal method, it can be seen that the phase delay and gain error did not appear.