• 대한전기학회논문지:전력기술부문A
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• 제55권10호
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• pp.410-417
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• 2006

Generally, the training set of maximum $m{\times}L(m+f)$ patterns in the pattern recognition method is required for the real-time bus reconfiguration strategy when a main transformer fault occurs in the distribution substation. Accordingly, to make the application of pattern recognition method possible, the size of the training set must be reduced as efficient level. This Paper proposes a methodology which obtains the minimized training set by applying the pattern clustering method to load patterns of the main transformers and feeders during selected period and to obtain bus reconfiguration strategy based on it. The MaxMin distance clustering algorithm is adopted as the pattern clustering method. The proposed method reduces greatly the number of load patterns to be trained and obtain the satisfactory pattern matching success rate because that it generates the typical pattern clusters by appling the pattern clustering method to load patterns of the main transformers and feeders during selected period. The proposed strategy is designed and implemented in Visual C++ MFC. Finally, availability and accuracy of the proposed methodology and the design is verified from diversity simulation reviews for typical distribution substation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 D
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• pp.2448-2450
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• 2002

In recent years, it has been a worldwide trend that many power utilities gave their attention to develop and operate their power plants, substation and distribution systems. Following this trend, KEPCO(Korea Electric Power Corporation) has developed many electric automation systems with various communication networks. It has been natural that the automation systems are just focused on to remote devices when they come to be designed. But, we have to shirt the focus to the automation system itself. There are many problems in maintenance and integration of the automation systems. When an automation system can't control some remote devices, there is no way to get why and which part(Master, Network, Master-side Modem or Remote-side modem, Remote Device, etc.) of the system has problems. Moreover the system just directly links to another automation system. If the system has to link many systems, it needs the linker per each systems. So, we need a new concept to resolve that problems, and develop the Intelligent and Integrated Gateway(IIG) for the automation systems for easy maintenance and integration.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 D
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• pp.2414-2416
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• 2004

Power Companies worldwide are undergoing tremendous change in the Automation issues. It becomes a worldwide trend that the power utilities focus their attention to the automation of their power plants and substation systems, employing recent advanced communication protocols. In this paper, we discuss the standard communication protocols which can be applied in the automation systems to help utilities reduce their operation and maintenance costs while at the same time meeting new requirements for communications to RTUs and intelligent electronic devices(IEDs). Especially, we introduce EC 61850 protocol which is developing for international standard by IEC.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1990년도 하계학술대회 논문집
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• pp.100-105
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• 1990

Associated with the protection and control functions in the substations, a new network scheme based on the IEEE 802.4 is proposed in this paper. This network is designed for supporting 3 data classes: 1st, it includes the highly time-critical data for the fault detection function. 2nd, routine data with a period is to served for monitoring the power status. Finally, it contains the control data which is used for reporting an event about protection or tuning some values related with power status. The way to allocate target_token_rotation timer is provided to guarantee the protection and control activities in the suggested network for the substation.

• 대한전기학회논문지:전력기술부문A
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• 제53권12호
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• pp.637-644
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• 2004

This paper proposes an expert system with the knowledge learning capability which can enhance the safety and effectiveness of substation operation in the automated substation as well as existing substation by inferring multiple events such as main transformer fault, busbar fault and main transformer work schedule under multiple inference mode and multiple objective mode and by considering totally the switch status and the main transformer operating constraints. Especially inference mode includes the local minimum tree search method and pattern recognition method to enhance the performance of real-time bus reconfiguration strategy. The inference engine of the expert system consists of intuitive inferencing part and logical inferencing part. The intuitive inferencing part offers the control strategy corresponding to the event which is most similar to the real event by searching based on a minimum distance classification method of pattern recognition methods. On the other hand, logical inferencing part makes real-time control strategy using real-time mode(best-first search method) when the intuitive inferencing is failed. Also, it builds up a knowledge base or appends a new knowledge to the knowledge base using pattern learning function. The expert system has main transformer fault, main transformer maintenance work and bus fault processing function. It is implemented as computer language, Visual C++ which has a dynamic programming function for implementing of inference engine and a MFC function for implementing of MMI. Finally, it's accuracy and effectiveness is proved by several event simulation works for a typical substation.

• 전기전자학회논문지
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• 제14권2호
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• pp.41-50
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• 2010

TETRA는 ETSI에서 제안한 디지털 주파수 공용 통신의 표준 규격이다. 현재 한국에서 전력IT 무선 백본 망으로 채택되었다. 경찰서와 소방서는 TETRA 망을 사용한다. 현재 전력자동화 프로토콜로는 배전 자동화에 사용되는 DNP3.0, 원격 검침에 사용되는 DLMS, 변전소 자동화에 사용되는 IEC61850 프로토콜이 있다. 이러한 전력 자동화 프로토콜들은 CDMA나 WCDMA 모뎀을 이용하여 송수신되고 있다. 만약 전력자동화 프로토콜을 TETRA 네트워크로 전송 한다면, 경찰서나 소방서와의 시스템과 상호 운용성을 확보할 수 있다. 그리고 재난 발생 시 효과적인 상황 대처를 가능하게 해줄 것이다. 따라서, 본 논문은 TETRA를 이용하는 전력자동화 프로토콜로 전송 할수 있는 전력자동화 게이트웨이 시스템을 제안한다.

• 전기학회논문지P
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• 제59권2호
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• pp.179-184
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• 2010

The digital substation automation system has contributed hugely to increasing the stability of power systems by providing not only protection and control of power systems but diagnostic features alongside them. Digital substation automation systems in the scale of substations consist of integrated operation systems and intelligent electronic devices. The main intelligent electronic devices currently in use are digital protection relays and the bay controllers in Gas insulated switchgears. Proficiently accomplishing the coordination of protection within the power system as a means of ensuring reliability and contriving for the stability of power supply through connection of function, the application of bay controllers is crucial, which collectively manage the protection relay at the bay level in order to achieve both. In this research, the bay controllers to be used in high-voltage Gas insulated switchgear has been localized, and in particular, the logic function and editor required in order to minimize the complicated hardware-like cable connections in the local panel have been developed. In addition, to ensure the strength and reliability of the bay controller hardware developed herein, the type tests from KERI have been successfully completed.

• 전기전자학회논문지
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• 제13권3호
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• pp.87-94
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• 2009

TETRA(TErrestrial Trunked RAdio)는 국내 전력IT무선기간망에 적용된 ETSI(European Telecommunications Standards Institute)가 정한 디지털 주파수공용통신(TRS, Trunked Radio System) 기술로서 공중망 및 기간망에 적용되고 있는 무선통신시스템이다. IEC 61850은 SCADA(Supervisory Control And Data Acquisition) 시스템에서 SAS(Substation Automation System)를 위해 제안된 프로토콜이다. 본 논문에서는 리눅스 운영체제 기반의 IEC 61850 Server와 Client Simulator를 사용하였다. 또한 IEC 61850 Server Simulator와 Client Simulator 간의 TCP/IP 기반의 통신을 TETRA Packet Data Service 기반의 통신으로 변환하는 다기능 게이트웨이를 개발하여 TETRA 기반 IEC 61850 SCADA 시스템을 구축하였다.

• 전기학회논문지
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• 제65권5호
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• pp.811-818
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• 2016

This paper suggests a structure of power control system in floating wave-offshore wind hybrid power generation system. We have developed an unified SCADA(Supervisory Control and Data Acquisition) system which can be used to monitor and control PCS(Power Conversion System) based on IEC61850. The SCADA system is essential to perform the algorithm like proportional distribution and data acquisition, monitoring, active power, reactive power control in hybrid power generation system. IEC61850 is an international standard for electrical substation automation systems. It was made to compensate the limitations of the legacy industrial protocols such as Modbus. In order to test the proposed SCADA system and algorithm, we have developed the wind-wave simulator based Modbus. We have designed a protocol conversion device based on real-time Linux for the communication between Modbus and IEC61850. In this study, SCADA system consists of four 3MW class wind turbines and twenty-four 100kW class wave force generator.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 D
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• pp.1901-1902
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• 2006

In recent years, it has been a worldwide trend that many power utilities gave their attention to develop and operate their power plants, substation and distribution systems. Following this trend, KEPCO(Korea Electric Power Corporation) has developed many electric automation systems with various communication networks. It has been natural that the automation systems are just focused on to remote devices when they come to be designed. But, we have to shift the focus to the automation system itself. We have developed the Multi-service Optical Transmission System (M-OTS) for electrical power systems. It can be adopt to not only distribution power field but also the transmission power field. The result strongly shows that the system is potentially beneficial in reliability, speed, and expandability. This paper presents some of initial design efforts and results toward a KEPCO's communication system in distribution areas.