Method and system for locating fault independent from parameter of multi-branch overhead line circuit of power distribution network

Abstract

The invention provides a method and system for locating a fault independent from a parameter of a multi-branch overhead line circuit of a power distribution network. Voltage and current measuring values and the total circuit length are obtained after a tail-end fault of the circuit, fundamental waves of voltages and currents of different ends are extracted, it is supposed that the faults occur indifferent sections, a proper range finding equation set is listed for each supposed fault section according to the Kirchhoff's current law and relation between the voltage and current of each phase and line impedance, fault positions and tapping point positions of different groups as well as the self-impedance and mutual impedance in unit length of each line are solved, and a fault point is located direction according to solutions of different sets. The method and system are higher in precision, and basically not influenced by the circuit parameters, fault position, transitional resistance andasymmetric fault type.

Description

technical field [0001] The present disclosure relates to a parameter-independent fault location method and system for empty lines of multi-split supports in a distribution network. Background technique [0002] With the continuous expansion of distribution network scale, branch lines have been widely used because of the economy and flexibility of power supply. Multi-branch line faults will affect the reliability of power supply and the operation of distributed power generation, and its complex line structure also makes fault location more challenging. Therefore, it is urgent to study multi-branch line fault location algorithms in distribution networks. [0003] Multi-branch fault location algorithms are divided into traveling wave method and impedance method. The traveling wave method judges the fault location based on the propagation speed and time of the fault traveling wave, but it relies on high sampling rate equipment, and because the distribution network line is short...

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Problems solved by technology

[0004] In fact, the line parameters will deviate from the initial value due to factors such as weather and line aging, and the management of line parameters in the distribution network is not as strict as that in the transmission network, and the line parameters and the location of the tap point are even unknown.

At the same time, considering that the measurement devices of multi-branch lines in the distribution network are generally arranged at the line outlets, not at the tap points, the existing method proposes a single-circuit line parameter-independent ranging algorithm that requires both ends of the section to be measured. Neither the proposed T-connection parameter-independent localization algorithm can be directly applied to multi-branch lines

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