THT-PXHK Biasing Magenetic Arc-suppression Coil Automatic Tracking Compensation Control Systerm is applied to neutral not grounding grid with 6kV to 66kV, and mine, coal, chemicals and medium and high voltage distribution network in large and medium-sized cities. When the grid is phase grounding, the system is used for automation track compensating capacitance current of phase grounding in grid, conduct best automatic compensation for capacitance current in grid to make residual current in fault point is less than 5 A, effectively restraining overvoltage of arc light and preventing phase fault. The system can be set according to the user’s requirements.