The medium voltage distribution system in the petrochemical industry usually adopts a neutral point non-effective grounding system, with the neutral point non-grounded or grounded via the arc suppression coil. When a single-phase-to-ground fault occurs, it will pose a threat to the normal operation of the power distribution system and equipment safety, and pose a threat to personal and property safety. The fault line selection technology proposed in the 1980s is an important means of dealing with single-phase earth faults in non-effective grounding systems. This paper analyzes the possibility of applying existing fault line selection technology to petrochemical industry distribution system, and focus on the traveling waves based fault line selection technology. According to the characteristics of the distribution system of petrochemical industry, this paper improves the line selection technology. Related simulations are conducted in this paper.

distribution system,single-phase-to-ground fault,fault line selection,travelling wave