Control strategy for optimized operation of traditional arc suppression coil of 35 kV grid

For traditional arc suppression coil (ASC) of 35 kV grid, it is difficult to give considerations to both neutral point voltage and extinguishing effectiveness of ASC. Therefore an optimized operation of ASC is presented in some papers to keep neutral point isolated under normal condition and to switch on the ASC upon single-phase-to ground fault (SF). However, these documnents don´t give any feasible control strategy. For this reason, concept of critical zero-sequence voltage (corresponding to the condition at which the arc of SF just fail to rekindle) is proposed and its calculation formula is deuced through analysis and calculation of 35 kV grid. And based on this concept the criteria for SF type is deduced through EMTP/ATP simulation and analysis. Then combining with proposed-in-this-paper compensation strategy of ASC, the control strategy for the optimized operation of traditional ASC is formed. Meanwhile, its engineering feasibility is verified with aid of EMTP/ATP simulation.