A Method of Improving Operation Performance of Current Differential Protection of Series Compensation Line

Abstract

The invention discloses a method for improving current differential protection motion performance of a series compensated line. The method comprises the steps that S1, after the series compensated line goes wrong and current differential protection is started, a first fault current and a second fault current on two sides of a fault point of the series compensated line are collected; whether the first fault current and the second fault current meet a protection criterion is judged, and if yes, current differential protection motions are conducted, and a circuit breaker trips; if not, the current differential protection motions are not conducted. According to the method, By the adoption of the protection criterion, when a system operates normally and alternatively external faults occur, the amplitudes of the currents on the two sides of the line are close to each other, the motion increment of the portion is close to zero, and the false action risk cannot be increased; when internal faults occur, because faults of current reversal of the series compensated line are all faults of fault points close to a series compensated installation position, the difference between the amplitudes of fault currents on the two sides is large, so that the motion increment of the portion can effectively increase the motion quantity, protection motion sensitivity is improved, the motion rejection risk is lowered effectively, and protection reliability is improved substantially.

Description

technical field [0001] The invention belongs to the technical field of relay protection for AC power transmission systems, and more specifically relates to a method for improving the operating performance of series-compensated line current differential protection. Background technique [0002] The installation of series capacitor compensation devices on transmission lines can improve the transmission capacity and system stability of ultra-high voltage long-distance transmission lines, and has a certain adjustment effect on the power flow distribution on transmission channels, so it has been more and more widely used. The device connected in series in the transmission line for the purpose of compensating the inductive reactance of the line, consisting of capacitors and their control and protection equipment, is called a series capacitance compensation device, or series compensation for short. The series compensation line refers to the transmission line equipped with a series ...

AI Technical Summary

Problems solved by technology

[0004] In view of the above defects or improvement needs of the prior art, the present invention provides a method for improving the operating performance of the current differential protection of the series-compensated line. Poor action performance and even protection may refuse to move

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