Uhv transmission line positive sequence and zero sequence parameter measurement method and system

Abstract

The invention concretely discloses a method and a system for measuring positive sequence parameters and zero sequence parameters of ultra-high voltage transmission lines. The method for measuring the positive sequence parameters comprises the following steps: measuring and calculating an end three phase short circuit and a first end applied three phase positive sequence power frequency voltage of the measured transmission lines to obtain a first end single phase positive sequence impedence voltage fundamental wave vector US1<+> and a positive sequence impedence current fundamental wave vector IS1<+>; measuring and calculating an end three phase open circuit and the first end applied three phase positive sequence power frequency voltage of the measured transmission lines to obtain a first end single phase positive sequence admittance voltage fundamental wave vector US2<+> and a positive sequence admittance current fundamental wave vector IS2<+>; measuring and calculating the values to obtain a measuring value rsd of first end single phase lead wire resistance of the measured transmission lines and a measuring value rmd of lead wire resistance from the end single phase to the short contact; solving the equation [rmd-b1(1+rmdb2)] y<2>+2y-b2=0 to obtain a positive sequence admittance coefficient y; and calculating a positive sequence impedence Z1 and a positive sequence admittance Y1 of the measured transmission lines. The method and the device can accurately measure the power frequency parameters of the ultra-high voltage transmission lines.

Description

technical field [0001] The invention relates to the field of high-voltage power transmission, in particular to a method and system for measuring positive-sequence and zero-sequence parameters of UHV transmission lines. Background technique [0002] Before the high-voltage transmission line is put into operation, in order to calculate the power flow distribution of the entire power grid system and set corresponding protection values ​​for the line, it is necessary to measure the power frequency parameters of the high-voltage transmission line. [0003] Line power frequency parameters of high-voltage transmission lines mainly include: DC resistance, positive-sequence impedance, zero-sequence impedance, positive-sequence capacitance, and zero-sequence capacitance of the transmission line, as well as mutual inductance impedance and coupling capacitance between double-circuit lines. [0004] The existing methods for measuring power frequency parameters are limited by the measurem...

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Problems solved by technology

[0023] However, compared with ordinary transmission lines, UHV transmission lines have the characteristics of long lines, high voltage, and large parameter values.

When the method described in the prior art is used to measure the power frequency parameters of UHV transmission lines, the generated errors are relatively large and the accuracy is relatively low

[0024] Therefore, the parameter measurement method described in the prior art is not suitable for power frequency parameter measurement of UHV transmission lines

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