10～35 kV voltage grade power system prrvent the arc overvoltage generally based on the size of single-phase current to the ground capacitor.So split-phase ground capacitor size of neutral point indirect earthing system needs to be measured.The measurement of split-phase earthing capacity for neutral point indirect earthing system via bias capacitor was introduced.The computing formula was obtained through analysis

and the actual system parameters were used for calculation.Compared with the test data

the calculated result proves that the measurement is simple and accurate without interrupting power supply to users.