Simulation Validation Study Of 35kV Arc Suppression Coil Selection

35kV system is the small current grounding system in our country. The neutral point generally should choose neutral non-grounding or neutral grounding via arc suppression coil mode. Furnishing arc suppression coil at neutral point of three-phase three-winding transformer, making the inductive current generated by the furnished arc suppression coil at 35kV neutral point and the grounding capacitive current counteracted, can reduce the zero-sequence current of single-phase to ground fault point, avoiding producing arc grounding overvoltage thus can significantly improve the power supply reliability of distribution network. Thereby, the choice of neutral grounding mode and arc suppression coil is also the important content of electrical primary design of transformer substation.This paper introduced transformer substation neutral grounding mode and the calculation method of 35 kV arc suppression coil selection. It introduced the features and use skills of Matlab/Simulink. It made theoretical analysis of neutral non-grounding system and neutral grounding via arc suppression coil system. It compiled Matlab calculation procedure of three-phase three-winding transformer model parameter and calculated three-phase three-winding transformer model parameter used to simulation. On the basis of the design data of 35kV distribution network of a 110 kV substation, using SimPowerSystems at the simulation platform of Matlab/Simulink, it set the neutral non-grounding and neutral grounding via arc suppression coil Matlab/Simulink circuit-simulation models of 35kV distribution network at Matlab simulation platform. It can be seen that circuit-simulation models and simulation results are correct and reasonable through the simulation run and simulation oscillograms. Simultaneously the simulation results also validated the zero sequence current's distribution rule of single-phase to ground fault of power distribution network. Utilize the results of Matlab/Simulink circuit-simulation models established in this paper to check the computed result of the choice of arc suppression coil when 35kV neutral point of a 110 kV substation grounds via arc suppression coil and through the contrast analysis we can see the simulation result is reasonable and it has practical reference value.