• 대한전기학회논문지:전력기술부문A
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• 제55권5호
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• pp.179-184
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• 2006

In a power system, an out-of-step condition causes a variety of risk such as serious damage to system elements, tripping of loads and generators, mal-operation of relays, etc. Therefore, it is very important to detect the out-of- step condition and take a proper measure. This paper presents a study on implementation of out-of-step detection algorithm using VHDL(Very high speed Hardware Description Language). The structure of out-of-step detection algorithm is analyzed for development of out-of-step detection relay on the FPGA(Field Programmable Gate Array). The out-of-step algorithm is separated to 4 parts: DFT IP, complex power calculation IP, out-of-step detection IP, control unit. Each parts are developed and simulated by using VHDL.

• 대한전기학회논문지:전력기술부문A
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• 제54권5호
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• pp.217-225
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• 2005

In a power system, an out-of-step condition causes a variety of risk such as serious damage to system elements, tripping of loads and generators, mal-operation of relays, etc. Therefore, it is very important to detect the out-of-step condition and take a proper measure. Several out-of-step detection methods have been employed in relays until now. Most common method used for an out-of-step detection is based on the transition time through the blocking impedance area in R-X diagram. Also, the R-R dot out-of-step relay, the out-of-step prediction method and the adaptive out-of-step relay using the equal area criterion (EAC) and Global Positioning Satellite (GPS) technology have been developed. This paper presents the out-of-step detection algorithm using the time variation of the complex power. The complex power is calculated and the mechanical power of the generator is estimated by using the electrical power, and then the out-of-step detection algorithm which is based on the complex power and the estimated mechanical power, is presented. This algorithm may detect the instant when the generator angle passes the Unstable Equilibrium Point (UEP). The proposed out-of-step algorithm is verified and tested by using Alternative Transient Program/Electromagnetic Transient Program (ATP/EMTP) MODELS.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.313-315
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• 2005

In a power system, an out-of-step condition causes a variety of risk such as serious damage to system elements, tripping of loads and generators, mal-operation of relays, etc. Therefore, it is very important to detect the out-of-step condition and take a proper measure. Several out-of-step detection methods have been employed in relays until now Mo,;t common method used for an out-of-step detection is based on the transition time through the blocking impedance area in R-X diagram. Also, the R-R dot out-of- step relay, the out-of-step prediction method and the adaptive out-of-step relay using the equal area criterion (EAC) and Global Positioning Satellite (GPS) technology have been developed. This paper presents the out-of-step detection algorithm using the time variation of the complex power. The complex power is calculated and the mechanical power of the generator is estimated by using the electrical power, and then the out-of-step detection algorithm, which is based on the complex Power and the estimated mechanical power, is presented. This algorithm, may detect the instant when the generator angle passes the Unstable Equilibrium Point (UEP). The proposed out-of-step algorithm is verified and tested by using Alternative Transient Program/Electromagnetic Transient Program (ATP/EMTP) MODELS.

• Journal of Electrical Engineering and Technology
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• 제6권2호
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• pp.167-173
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• 2011

This paper presents a method for the development of the impedance locus to test the dynamic characteristics of protective relays. Specifically, using the proposed method, the impedance locus can comprise three impedance points, and the speed of impedance trajectory can be adjusted by frequency deviation. This paper is divided into two main sections. The first section deals with the configuration of impedance locus with voltage magnitude, total impedance magnitude, and impedance angle. The second section discusses the control of the locus speed with the means of the deviation between two frequencies. The proposed method is applied to two machine equivalent systems with offline simulation (i.e., PSCAD) and real-time simulation (i.e., real-time simulation environment) to demonstrate its effectiveness.

• 대한전기학회논문지:전력기술부문A
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• 제51권9호
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• pp.451-459
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• 2002

This paper presents a method for modelling of the impedance locus in order to test the protective relay with dynamic. This paper has the two parts, the first part is the configuration of impedance locus with voltage magnitude, total impedance magnitude and angle. And the second part is the control of the locus speed with deviation of two frequencies. The proposed method is applied to two machine equivalent system with PSCAD/EMTDC to show its effectiveness.