Zero-sequence parameter measurement method for double-circuit part of the same tower line based on non-uniform transmission line

Abstract

The invention discloses a double-circuit portion same-tower line zero-sequence parameter measurement method based on a non-uniform transmission line. By use of a power-failure measurement mode, the head end and the tail end of the line are in a three-phase short circuit, a single-phase power supply is applied to the head segment of a circuit line, according to a measurement mode given by the method, zero-sequence voltages and zero-sequence currents of the head end and the tail end of a double-circuit power transmission line are simultaneously measured, and by use of a GPS synchronous time service function, synchronous sampling on line double-end voltages and currents is realized. By use of double-end synchronous measurement data, by use of a calculation method given by the method, zero-sequence resistance, zero-sequence inductance and zero-sequence capacitance of a double-circuit portion same-tower line power transmission line are calculated. According to features of the zero-sequence parameters of the double-circuit portion same-tower line, non-uniformity of the line parameters is taken into consideration, a distributed parameter model based on a non-uniform transmission line is established, by use of a Laplace transform method, a transmission line equation is solved, and thus the measurement precision is greatly improved.

Description

technical field [0001] The invention belongs to the technical field of power system measurement, and in particular relates to a method for accurately measuring zero-sequence parameters of a double-circuit transmission line on the same tower. Background technique [0002] The transmission line is one of the main components of the power system, and it is also the carrier of power transmission, which plays a great role in the power system. The zero-sequence parameters of the transmission line are affected by many factors, including the geometric shape of the transmission line, current, ambient temperature, wind speed, lightning protection line erection method and line path, etc. depth, and the soil resistivity cannot be determined, so the relevant regulations in our country stipulate that the zero-sequence parameters of the line must be measured. [0003] With the continuous development of the power system, the contradiction between land resources and transmission corridors is...

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Problems solved by technology

[0004] The purpose of the present invention is to overcome the drawbacks that the prior art uses a uniform transmission line model, which cannot be applied to the measurement of zero-sequence parameters of non-uniform transmission lines, and at the same time overcomes the measurement accuracy caused by the distribution effect when the existing method is applied to long-distance lines reduce the problem, a method for accurate measurement of zero-sequence parameters of double-circuit lines on the same tower is proposed

The method of the present invention can be applied to the double-circuit part of the same-tower transmission line with any distance; it solves the problem of simultaneity of signal measurement in different places; it can measure zero-sequence resistance, zero-sequence inductance and zero-sequence capacitance, a total of 9 zero-sequence parameters at one time

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