Series-compensation double-circuit line fault locating method based on distributed parameter model

Abstract

The invention discloses a series-compensation double-circuit line fault locating method based on a distributed parameter model. The method comprises a step I, a six-sequence component method is adopted to perform decoupling, and a reverse voltage cross a bus on two sides is zero when a fault occurs in a circuit after the decoupling is performed; a step II, according to characteristics that voltages at a fault spot are equal and currents at two ends of a series compensation device are reverse and which are respectively reckoned from the two sides, a series compensation voltage and the currents at the two ends in a transmission equation are eliminated; and a step III, by utilizing a pure resistance property of a transition resistor at a position of the fault spot and a fault timing sequence network boundary condition, a fault locating function when double-circuit lines containing series compensation are erected on the same pole is constructed, and a fault distance is solved by utilizing the fault locating function when the fault occurs. The method does not rely on a model of the series compensation device and is not influenced by MOV nonlinearity, a position of the fault spot relative to the series compensation does not need to be known in advance, the ranging principle is simple, one-dimensional searching for the fault distance is needed only, and a pseudo root discrimination problem does not exist.

Description

technical field [0001] The invention relates to the technical field of fault location of a series compensation double circuit line, in particular to a method for fault location of a series compensation double circuit line based on a distributed parameter model. Background technique [0002] The series capacitor compensation device (series compensation) is installed on EHV and UHV transmission lines, which can improve line transmission capacity and system transient stability, reduce line loss, and realize line power flow optimization. The 220kV~735kV transmission lines in the United States, Sweden, Canada and other countries have widely used series capacitor compensation equipment. Unfolding, a large number of line structures with series compensation and double-circuit lines on the same pole have appeared. [0003] The series compensation line has a long transmission distance and is often connected with large power plants and load centers. If the fault cannot be repaired in ...

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Problems solved by technology

The above research mainly focuses on the single-circuit line of transmission lines, while in the field of double-circuit line research, the literature "Fault location on double-circuit series-compensated lines using two-end unsynchronized measurements" calculates the double-end unsynchronized angle through the data before the fault, and obtains the fault location by solving the fault circuit equation and transition resistance, in which the zero-sequence network adopts an approximate distributed parameter model, without considering the zero-sequence mutual impedance between the two circuit lines, the ranging accuracy obtained by such processing is relatively low; A fault location method for series-compensated double-circuit lines based on distributed parameters. This method does not rely on the series-compensated model. Assuming that the fault type is known, the symmetrical component method is used to obtain different measured distances by using the boundary conditions of different fault types. Due to the wide variety of double-circuit line faults, this method is not very applicable and needs to exclude pseudo-roots. Further calculations and comparisons for eliminating pseudo-roots are cumbersome

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