Abstract:

      Correct identification of faulttype for ±800 kV ultrahigh voltage direct current transmission lines is an important guarantee for safe and stable operation of state grid. We investigate transient characteristics analysis and fault identification principle of transient voltage and transient energy for not easy to action and easy false action issues of a traveling wave protection device. We then employ the matterelement model from extension engineering to fuse the two faulttype identification criteria based on the principle of extension engineering. We eventually present a faulttype identification criterion to distinguish singlepole ground fault, doublepole ground fault, fault lightning stroke and nonfault lightning stroke.

Key words: ultrahigh voltage direct current transmission line, fault type, extension engineering, matterelement model