• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.252_253
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• 2009

각 송전선로의 임피던스 변화에 대한 과부하 선로 조류의 민감도를 통하여 과부하 선로를 해소하기 위한 여유 송전선로의 투입과 운전 중인 선로의 차단을 한꺼번에 체계적으로 수행하는 민감도와 스위치 상태변경을 최소화하는 스위칭의 알고리즘이 제시된다. 이를 통해 수많은 케이스의 스위칭 경우의 수를 대폭적으로 줄임으로써 효율적으로 선로 스위칭을 수행하여 효과적인 과부하 해소 대책을 세우는 기법을 제시한다. 이 기법을 IEEE 39 모선 시스템에 적용하여 제시된 알고리즘의 효과를 보여준다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.8
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• pp.96-103
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• 2008

In this paper, a new algorithm based on sensitivity method for alleviating overloads in power networks is presented to find the switching branches effectively. By applying the new sensitivity of the line flow with respect to the change of the branch impedance, both on and off switchings for alleviating overloads in power networks are performed systematically at once and an effective scheme for drawing up a plan to alleviate overloads of the lines is presented through screening a large number of line switching cases easily. The ranking of switching branches is calculated according to the new switching algorithm based on sensitivity method and the switching of the ranked branches is performed in the order of ranking until overloads are eliminated. In order to show the effects of this algorithm, it is applied to a small scale power system of IEEE 39-bus test system.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.8 no.5
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• pp.70-75
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• 1994

본 논문은 상정사고에 기인한 선로의 과부하 해소 대책을 수립함에 있어서 가능한 한 부하차단없이 발전력재배분만으로 과부하해소를 시도하는 새로운 앨고리즘을 제시한다. 신속한 발전력 변화분을 계산하기 위하여 선로 과부하량과 상태변수($\Delta$$\theta$) 및 상태변수($\Delta$$\theta$)와 발전력 사이의 선형적인 관계를 이용하여 우선 과부하선로 양단모선 전압의 위상각 변화분을 계산하고 이에 대한 발전력 변화분을 계산하였다. 이 때 모든 Jacobian요소를 계산하지 아니하고 과부하선로 양단 모선번호에 해당하는 2열의 요소중 발전기 모선(slack 모선 제외)번호에 해당하는 행의 요소만 구함으로써 최소한의 요소를 이용하여 신속하게 계산토록 하였다.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.5
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• pp.459-467
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• 1992

This paper presents a new algorithm for the countermeasure to alleviate the line overloads due to contingency without shedding loads in a power system. This method for relieving the line overloads by line switching is based on obtaining the kine outage distribution factors-the linear sensitivity factors, which give the amount of change in the power flow of each line due to the removal of a line in a power system. There factors are made up of the elements of sparse bus reactance matrix and brach reactances. In this paper a fast algorithm and program is presented for obtaining only the required bus reactance elements which corresponds to a non-zero elements of bus admittance matrix, and elements of columns which correspond to two terminal buses of the overloaded(monitored) line. The proposed algorithm has been validated in tests on a 6-bus and the 30-bus test system.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.36 no.6
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• pp.381-389
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• 1987

This paper presents a method for optimal load shedding in preserving a system security following abnormal condition as well as a sudden major supply outage. The method takes account of static characteristic of generators control and voltage and system frequency characteristic of loads. The optimization problem is solved by a gradient technique to get the maximal effect by the least quantity of load shedding considering line overloads as well as voltage disturbances and system frequency. The method is illustrated on a 8-bus system. It has been found that the use of the proposed algorithm for model systems alleviate the line overload more efficiently than the former method. It is believed that this method will be useful in security studies and operational planning.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.11
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• pp.2007-2016
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• 2011

In this paper, a new algorithm for alleviating overloads in power networks by the use of line power tracing and sensitivity is proposed to perform line switching and bus separation effectively. Also, a new bus separation index based on line power tracing is presented to find the bus to be separated for relieving overloads effectively. By applying the sensitivity of the line flow with respect to the change of the line impedance, both switching-on and switching-off of the lines for alleviating overloads in power networks are performed systematically at once. The number of the considered cases for line switching and bus separation can be greatly reduced and the best combination of line switching and bus separation can be acquired efficiently by the use of the sensitivity and the bus separation index. In order to show the effects of this algorithm, it is applied to a small scale power system of IEEE 39-bus system and practical power systems of KEPCO.

• Proceedings of the KIEE Conference
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• 1999.07c
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• pp.1023-1025
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• 1999

This paper provides the steady-state UPFC model referred as UPFC injection model for power flow control. The application of UPFC for the line overload alleviation is demonstrated through a numerical example. It is shown that UPFC has the capability of regulating the power flow, therefore alleviating the line overload.

• Proceedings of the KIEE Conference
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• 1995.07b
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• pp.588-590
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• 1995

This paper presents a new algorithm for the countermeasure to alleviate the line overloads in a power system. This method utilizes network sensitivity factors which are establised from DC load flow solutions. The line outage distribution factors(LODF) are formulated using changes in network power generations to simulate the outaged line from the network. The proposed algorithm has been validated in tests on a 6-bus test system.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.432-436
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• 1991

This paper presents a new algorithm for the countermeasure to alleviate without shedding system loads the line overloads due to contingency in power system. This method for relieving by line switching is based on obtaining the line outage distribution factors - the linear sensitivity factors, which give the amount of change in the power flow of each line due to the removal of same other line in the power system. These factors are made up of the elements of Bus Reactance Matrix and branch reactances. In this paper a fast algorithm and program is presented for obtaining only the required Bus Reactance elements which corresponds to a non - zero elements of Bus Admittance Matrix and elements of columns which correspond to two terminal Buses of the overloaded(monitored) line. The proposed algorithm has been validated in tests on the 6 busbar test system