The Research and Development of the High-Speed Transmission Line Protection Based on the Transient Information

The ultra-high-speed transmission line protection based on the concept of the equal transfer is proposed, including the distance protection based on the differential algorithm applying the local transient information and the sample value differential protection applying the two-terminal transient information. The method of the equal transfer processes is utilized to solve the impact of the CVT transient transfer error and the transmission line distributed capacitor, in order to improve the speed and the accuracy of the protection. In addition, the accelerating operation scheme for the near-zone three-phase fault is proposed. The proposed transmission line method is realized in the existing protection hardware and software platform. The laboratory test shows that the protection based on the local information can operate within 2.7ms for the near-zone fault, and the differential protection can cut-off the full-line fault within less than 5.8ms. This new protection technology can be adapt for the scenario in the power-electronized grid that the fault transient is complex and the protection is demanded to operate quickly.