Combination Operation for neutral point of 35kV grids in mountainous area

Based on a lot of measurement and analysis, This paper find that the unbalanced nature of 35 kV grids due to unsymmetrical capacity values gives difficulty in neutral point operation in mountainous area of west China. Improving compensation of suppressing coil can rectify imbalance of voltage but bring up new problem that suppressing coil can not extinguish grounding arc effectively in fault. To put down contradiction mentioned above, This paper proposes a new neutral point operation method as neutral point insulated in routine operation and suppressing coil grounding in fault, then EMTP simulation acts. Simulation indicates that new neutral operation method can improve lightning withstand level and decrease trip-out rate of grids.