Acceleration method of symmetric opening in distance protection oscillation lock

Abstract

The invention relates to an acceleration method of symmetric opening in a distance protection oscillation lock. First acceleration soft switches are connected on both ends of a time element in parallel, wherein the input end of each acceleration soft switch is connected with the output end of a No. 2 and gate, the input end of the No. 2 and gate is respectively connected with the output end of a No. 1 and gate and the output end of an or gate, the input end of the or gate is respectively connected with the output end of a mutation capacity and delay component, the input end of the delay component is connected with the output end of the No. 2 and gate, the control basis of the mutation capacity is to calculate through point sampling arithmetic to control the mutation output so as to control not gate output, control the output of the No. 2 and gate to close the acceleration soft switches, and finally cut of a No. 1 fault line; and the control process prevents the error closing of the acceleration soft switches by the combination of sampling mutation short-termed broadening and distance protection action control holding. The method can accelerate the symmetric opening in the oscillation lock, and facilitates the quick removal of faults.

Description

technical field [0001] The invention relates to a symmetrical opening method of oscillation blocking in distance protection, in particular to an acceleration method for symmetrical opening of oscillation blocking in distance protection, which is specifically applied to the acceleration of symmetrical opening of oscillation blocking when a three-phase short-circuit fault occurs in a power system. Background technique [0002] When the power system is disturbed, the phenomenon of losing synchronization between two systems running in parallel is called oscillation. When oscillating, the power angle δ changes periodically between 0° and 360°. When δ is near 180°, it will cause the impedance relay Z to act incorrectly, which will have a serious impact on the transmission line. At present, our country adopts the method of oscillation blocking to deal with system oscillation. For a long time, due to its simple control principle and reliable operation, the oscillation blocking devic...

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Problems solved by technology

Although the two schemes included in this method can be automatically switched and selected by the instructions set in the microcomputer software program according to the size of the set impedance, it has a wide range of adaptation, but when a fault occurs during oscillation and needs to be blocked and then opened, if a three-phase For short-circuit faults, the symmetrical opening adopted in this invention still requires a short delay time, and this delay time is generally several hundred milliseconds, which is relatively long, which is very unfavorable for troubleshooting, resulting in significant losses

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