Power grid line wide-area relay protection method suitable for triple-line fault tripping

Abstract

The invention discloses a power grid line wide-area relay protection method suitable for triple-line fault tripping. According to the method, firstly, a power grid wide-area measuring system is utilized for synchronously measuring voltage and current phasors of transformer substations of a power grid, and power grid synchronization data are obtained; if triple-line fault tripping continuously happens to the power grid, a wide-area backup protection system calculates an incidence matrix between line currents of the power grid, contribution components of the currents on triple fault lines on variable quantities of the currents of the lines of the power grid are respectively calculated, then the variable quantities, obtained after triple-line fault tripping, of the currents flowing through the lines of the power grid are calculated, and then the variable quantities, obtained by calculation, of the currents of the lines and the variable quantities, obtained by actual measurement, of the currents of the lines are utilized for forming a relay protection criterion. According to the method, after triple-line fault tripping happens to the power grid, and large changes happen to a power grid topological structure, power grid parameters generated before triple-line fault tripping are utilized for directly calculating the variable quantities, obtained after triple-line fault tripping, of the currents of the lines of the power grid, the calculation time is short, and the protection motion speed is high.

Description

technical field [0001] The invention relates to the technical field of electric power system relay protection, in particular to a wide-area relay protection method suitable for triple line fault tripping power grid lines. Background technique [0002] The task of relay protection is to reflect the failure and abnormal operation 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 the possibility of failure o...

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 even the protection mismatch or insufficient sensitivity may occur

[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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