Measuring phase-to-ground capacitance based on displacement voltage method

In order to make sure the best compensation for the grounding fault current, neutral resonant grounding mode via the arc suppression coil is widely used in medium and low voltage distribution network in our country. The key problem is measuring the phase-to-ground capacitance accurately online. Displacement voltage is a method of measuring the phase-to-ground capacitance indirectly. Choosing the suitable inductive reactance is very important to calculation accuracy. The model of neutral resonant grounding is established with the simulation software in this paper. The inductive reactance and the displacement voltage corresponding to reactance are recorded. This paper used non-linear regression method to fit the multinomial between displacement voltage and the reactance. The resonance point can be determined to get the suitable reactance for capacitance calculation. It can improve the calculation accuracy and reduce the error.