A new protection criterion for high-voltage transmission line using two-end voltage transients

A new transient based protection criterion for high voltage transmission line based on the wavelet transform results of voltage transient signals at the two ends of the line is presented. The difference of high frequency voltage transients at the two ends of the transmission line when in-zone faulted and out-zone faulted is analyzed, and the transient voltage content ratio and transient voltage singularity ratio are deduced. Two-end transient voltage protection criterion using the transient voltage singularity ratio is proposed, and the principles of the protection settings are given. The calculation of transient voltage content ratio and transient voltage singularity ratio using wavelet transform is deduced. Simulations of different fault locations and different fault types are carried out for testing and analyzing the protection criterion.