Double end testing method in power transmission line longitudinal difference protection

Abstract

This invention relates to a method for testing double ends in the translay protection of a transmission line including: 1, a protection device transfers the sample values of three-phase current and three-phase voltage, 2, the device computes the theta of the double side voltage based on their sample values when the voltages of both sides are larger than the designed threshold, 3, one side shifts theta of the AC voltage sent by the opposite, then the voltage phases applied by the two-side test instruments are equal, therefore, a unified voltage phase primary standard is set up for the AC output of the instruments, 4, the protection device takes the voltage phasor phase of the two sides as the primary standard of the current phase to adjust the current phase, and a relay protection device can rectify the phase between the voltage and current of its side to carry out the test for protecting both ends, 5, triggering the two-end test.

Description

technical field [0001] The invention relates to a double-terminal test method in the longitudinal differential protection of transmission lines in the electrical field, in particular to a convenient on-site test method provided by adding a double-terminal test function module in the relay protection of a high-voltage power grid, and a built-in double-terminal test method in the protection device The implementation method of the test module. Background technique [0002] The reliability of relay protection devices in high-voltage transmission systems is the guarantee for the safe and stable operation of power systems. Years of on-site operation experience tell us that the reliability of the protection device not only depends on the correctness of the principle and implementation method of the protection device itself, but also depends on the correct wiring of the secondary circuit of the relay protection. Before the relay protection device is put into operation and during th...

AI Technical Summary

Problems solved by technology

Due to the influence of economic and geographical factors, this method is rarely used in the field

A Japanese company's optical fiber differential protection device outputs a phase trigger output terminal and a time trigger output terminal. However, during the test, it is necessary to manually adjust the output phase of the relay protection test instrument on one side with the help of an oscilloscope, and the test operation is more cumbersome.

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