Research on HV line protection relay based on characteristic of main transient frequencies

GAO Xiao-hai1， ZHANG Xue-song2， ZHANG Bo1， WANG Hui-fang1， HE Ben-teng1
（1. College of Electrical Engineering， Zhejiang University， Hangzhou 310027， China；
2. Zhejiang Electric Power Test and Research Institute， Hangzhou 310014， China）

Abstract： The transient component on the high voltage（HV） transmission line is represented as a series of main transient frequencies in the frequency domain. Aiming at studying the feasibility and reliability of a protection scheme based on those frequencies，the transient characteristic of the fault HV transmission line was firstly analyzed，a relationship between fault distance and main frequencies was put forward，which indicating the size of those series of main transient frequencies can determine the size of the fault distance. Thus the distance by getting the size of a certain main transient frequency was calculated. Then the factors that influence the reliability of the protection scheme were studied and some measures to reduce the influence were advised. A simulation of ATP was carried out to prove the feasibility of this method. The results indicate that the method referred meets the demand of fast speed quality and the fault distance measurement error is related to factors like the precision of the transient frequency，the distance of the fault and the size of the main transient frequency.
Key words： high voltage（HV） line； transient component； protection relay； fault distance measurement； main transient frequencies； Fourier transform