Single-phase-to-earth fault location method of t-connection line based on multi-time section information

Abstract

A single-phase-to-ground fault location method for T-connected lines based on multi-time cross-section information; for the action mechanism of single-phase tripping of all three-terminal circuit breakers on the transmission line and single-phase automatic reclosing after a single-phase grounding fault occurs on a T-connected transmission line, it is assumed that The three-terminal system of the T-connected transmission line is named M, N, and K terminals respectively. First, the three-phase voltage and three-phase current of the three time sections are collected at the M terminal as the input; the voltage, current positive, negative, and The zero-sequence electrical equation system is established to describe the relationship between the voltage and current of the three terminals of the transmission line; taking the power supply potential of the N-terminal and K-terminal, the equivalent system impedance, the fault distance and the transition resistance as unknown quantities, solve the established nonlinear electrical equations, we get Accurate fault location results are obtained; the method of the present invention only uses single-ended electrical quantities and does not require multi-terminal communication and synchronization technology, that is, it can provide high-precision fault distance and transition resistance value, and can effectively solve the fault location of T-connected transmission lines. the problem.

Description

technical field [0001] The invention belongs to the technical field of power system protection and control, and in particular relates to a single-phase grounding fault ranging method of a T-connection line based on multi-time section information. technical background [0002] At present, environmental problems continue to intensify, conventional energy sources are increasingly depleted, and the development of renewable energy is in urgent need. With the gradual maturity of wind power technology and the rapid progress of equipment level, the cost of wind power generation continues to decrease, and wind power occupies an increasingly important position in the energy structure. The site selection of wind farms is mainly affected by wind resources. The grid-connected modes of megawatt-scale wind farms are mainly divided into two categories: one is represented by the Jiuquan Wind Power Base in Gansu Province, which adopts the 330kV substation as the center radial feed-out mode, a...

AI Technical Summary

Problems solved by technology

However, in practical applications, single-ended electrical quantity protections such as distance and zero sequence are only configured on the transmission line system side, and no reclosing is used. The wind farm side is equipped with circuit breakers and communication channels, but no protection is configured. The wind farm side circuit breaker is used to isolate faults, and the information on the wind farm side is difficult to obtain in real time. It is impossible to perform distance measurement based on multi-terminal information synchronization and sharing. Only the measurement data on the system side can be considered for single-end fault distance measurement.

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