Study On Distribution Networks Off-Line Fault Location Based On Signal Injection

Power failure of electrical network can cause huge pecuniary loss,so it's strongly needed for prompt fault location and removement.In distribution networks,fault of single grounding phase occurs most frequently,so the study of this area is very significant.Usually we can use traveling wave method,signal injection method and fault indicator technology to locate the fault,but each of these method has it's shortcomings when facing the most difficult problem of distribution networks-too many branches, long lines and large grouding resistance,so non of them can solve distribution networks fault location problem thoroughly.Research reveals that DC method can solve all these problems,so it can be used in fault location of any network structure and fault resistance.In this article simmulation and field test are carried on to prove the feasibility of this method.On the basis of DC location method,60HZ AC location method is promoted to simplify fault location operation and shorten the time needed and the fault location efficiency will be enhanced,because the signal can be detected on the ground.As to the fault pole location,60HZ detection equipment and CT method can be used.