Anti-interference measurement method for zero sequence impedance of super-high-voltage/ultrahigh-voltage multi-loop power transmission line

The invention provides an anti-interference measurement method for the zero sequence impedance of a super-high-voltage/ultrahigh-voltage multi-loop power transmission line, which comprises the following steps of: firstly powering off the power transmission line; shorting and grounding three phases at the tail end of the line; shorting the three phases at the head end of the line; applying voltageto the head end of the power transmission line by directly using a single-phase power frequency power supply of a transformer substation where a voltage-application point of the power transmission line is located; and measuring zero sequence voltage applied to the head end of the power transmission line and zero sequence current applied to two ends of the power transmission line at the same time.In order to eliminate the influence of power frequency interference, when the zero sequence impedance is measured, harmonic components included in data of the measured zero sequence current and zero sequence voltage are utilized to calculate harmonic zero sequence impedance of the power transmission line, and finally the harmonic zero sequence impedance is converted into power frequency zero sequence impedance of the power transmission line.