Zero sequence parameter of transmission line is an important foundation for short-circuit current calculation on open phase running

opening and closing current calculation on open phase running

short-circuit ground fault location

and zero sequence protection setting calculation. For the interference problem of zero sequence parameter measurement in 1 000 kV Wannan-Zhebei UHV transmission line

in this paper

a "shunt capacitor compensation combined with large-capacity variable-frequency power source"measuring method is proposed. Test data analysis results show that the use of large-capacity power source can improve the signal-to-noise ratio of measuring signal

and reduce the influence of the interfering voltage caused by adjacent lines. The use of parallel capacitance compensation method can reduce the influence of the induced current caused by adjacent lines on the impedance parameter measurement. The measurement results of power frequency method and non-power frequency method is closer

but there are some differences between the test results and the calculated values. For the zero sequence parameter test of Wannan-Zhebei UHV transmission line

it is appropriate to adopt the test results obtained by nonpower frequency method. Field test results verify the effectiveness of the proposed zero sequence parameter measurement method.