High voltage direct current(HVDC)transmission line has a long distance

great differences in terrain

geomorphology

environment and climate. It has high probability of failure and needs high accuracy for fault location. So

the wave equation describing the electrical characteristics of the distributed parameter line is put forward

which is the basis of fault location principle. According to the time

frequency and space

the traveling wave methods

natural frequency methods and fault analysis methods are summarized. It makes clear that the main fault location method in real application should be traveling wave method

and the others assist to improve the reliability of overall fault location. Then

the follow-up ideas and programs to improve several existing problems are also presented

such as pickup in high resistance grounding fault

oscillation of initial wave head

and frequency change of reflection coefficient.