Current phase comparison based pilot protection had been generally utilized as primary protection of the transmission lines in China from the 1950’s to the 1980’s. Conventional phase comparison pilot protection has ...Current phase comparison based pilot protection had been generally utilized as primary protection of the transmission lines in China from the 1950’s to the 1980’s. Conventional phase comparison pilot protection has a long phase comparison time, which results in a longer fault-clearing time. This paper proposes a new current phase comparison pilot protection scheme that is based on non-power frequency fault current component. The phase of the fourth harmonic current of each end of the protected line has been abstracted by utilizing complex wavelet transformation and then compared in order to determine whether the inner fault occurs or not. This way can greatly decrease fault-clearing time and improve performances of this pilot protection when fault occurs under the heavy-load current and asymmetrical operation conditions. Many EMTP simulations have verified the proposed scheme’s correctness and effectiveness.展开更多
基金Sponsored by the Power Electrical Science and Technology Foundation of XJ Group and the Shanghai University Foundation for Excellent Young Teacher.
文摘Current phase comparison based pilot protection had been generally utilized as primary protection of the transmission lines in China from the 1950’s to the 1980’s. Conventional phase comparison pilot protection has a long phase comparison time, which results in a longer fault-clearing time. This paper proposes a new current phase comparison pilot protection scheme that is based on non-power frequency fault current component. The phase of the fourth harmonic current of each end of the protected line has been abstracted by utilizing complex wavelet transformation and then compared in order to determine whether the inner fault occurs or not. This way can greatly decrease fault-clearing time and improve performances of this pilot protection when fault occurs under the heavy-load current and asymmetrical operation conditions. Many EMTP simulations have verified the proposed scheme’s correctness and effectiveness.
