Characteristic Analysis of Arc Grounding Fault in Distribution Network

Abstract

With the acceleration of urbanization, the voltage level of transmission lines is continued to rise. The arc cannot be "self-extinguished" smoothly, causing serious damage to the system. Therefore, it is very important to study the characteristics of arc for the safe and stable operation of system. The Cassie and Mayr arc models are established through PSCAD, and through comparative analysis, the arc models suitable for distribution networks at different voltage levels are obtained. Cassie arc is suitable for simulating arc grounding faults in medium-voltage distribution networks with high arc voltage, and Mayr arc is suitable for simulating Arc ground fault in low voltage distribution network with low arc voltage. In addition, the characteristics of neutral point grounding through transition resistance, neutral point ungrounded , arc grounding fault through arc suppression coil are studied, by building a distribution network model, simulating single-phase grounding faults. The simulation results show that the use of the neutral point to ground through the transition resistance in the distribution network can greatly limit the overvoltage, reduce the requirements for the degree of insulation of the system, and improve the reliability of the system operation. The neutral point is grounded through the arc suppression coil, which can limit the over-voltage and short-circuit current to a certain extent. Compared with other methods, the damage to the system is the lowest.