Grid circuit overload maloperation-preventing relay protection method based on wide-area information

Abstract

The invention discloses a grid circuit overload maloperation-preventing relay protection method based on wide-area information. According to the method, an existing wide-area measuring system of a grid is used for synchronously measuring the phasor quantity of the voltages and the phasor quantity of the currents of all transformer substations at first; if a grid single circuit trips, a wide-area backup protection system sequentially calculates the corrected impedance, the corrected admittance and the compensation voltage; voltages of all nodes of the grid of which the circuit has not tripped and the compensation voltage are superposed to obtain the voltage phasor quantities of all transformer substations of the grid which tripped; the currents flowing through all circuits in the grid are calculated and combined with circuit currents measured by the existing wide-area measuring system to form overload maloperation-preventing protection criteria. According to the grid circuit overload maloperation-preventing relay protection method based on the wide-area information, the protection action speed is high, the circuits can be reliably shut before ciruit overload protection maloperation occurs, other circuits are protected against overload and mistaken cutting, wherein the overload is caused by transferring of the currents after the grid single circuit tripped, and the large-area power failure of the grid is effectively prevented.

Description

technical field [0001] The invention relates to the technical field of electric power system relay protection, in particular to a wide-area information-based relay protection method for overload prevention and maloperation of power grid lines. Background technique [0002] The task of relay protection is to reflect the failure and abnormal operation status of the protected components. According to the function, it can be divided into main protection and backup protection. Among them, the main protection is only responsible for the task of quickly removing the faults of the protected components, and is basically not affected by the operation mode of the system. With the application of fiber optic channel, the main protection technology of high-voltage and extra-high-voltage systems based on double-terminal electrical quantities has become more and more mature. The backup protection is also responsible for the remote backup protection of adjacent electrical components. Due to...

AI Technical Summary

Problems solved by technology

[0003] 1) The coordination relationship of backup protection is complex and the action time is long

In severe cases, it may not meet the limit cut-off time required by the stability of the power system, and then become a hidden danger to the safety of the large power grid

[0004] 2) It is very difficult to configure and set the backup protection, and it cannot track the changes in the operation mode of the power system, and there may even be protection mismatch or insufficient sensitivity

[0005] 3) The backup protection cannot distinguish between the internal fault and the power flow transfer caused by the fault removal, which may lead to chain tripping of the backup protection under heavy load conditions

[0006] In a blackout accident, although the backup protection of the power system operates correctly according to the design principles, it objectively accelerates the system collapse.

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