Judgment method of non-full phase of circuit breaker based on the rate of change of fundamental voltage amplitude on both sides

Abstract

The invention discloses a circuit breaker non full phase judging method based on a two-side voltage fundamental wave amplitude change rate. A protection device is used for measuring three-phase voltage and open delta voltage at the left side and the right side of the circuit breaker; fundamental wave amplitudes of the three-phase voltage and the open delta voltage at the left side and the right side of the circuit breaker and the change rate of the fundamental wave amplitudes of the open delta voltage at the left side and the right side are calculated respectively; when the fundamental wave amplitudes of the three-phase voltage at the left side and the right side are both larger than eta% of rated voltage, the fundamental wave amplitudes of the open delta voltage at the two sides are both larger than a fundamental wave amplitude threshold, and the fundamental wave amplitude change rate of the open delta voltage at either side of the left side and the right side is larger than a change rate fixed value threshold at the corresponding side, non full phase of the circuit breaker is judged, and alarming or tripping is carried out after a short time delay t.

Description

technical field [0001] The invention belongs to the field of relay protection of electric power systems, in particular to a method for judging the incomplete phase of a circuit breaker based on the rate of change of the amplitude of the voltage fundamental wave on both sides. Background technique [0002] At present, the non-full-phase protection of circuit breakers widely used in the field is generally composed of three-phase inconsistent contacts and negative sequence current criteria. Very small, it is difficult to exceed the negative sequence current setting value, and it is impossible to judge that the circuit breaker is not in full phase. Generator machine-side circuit breakers are generally three-phase linkage, do not provide three-phase inconsistent contacts, and cannot adopt traditional non-full-phase protection. There have been many accidents in the field where one-phase tie rod of the machine-side circuit breaker broke and caused non-full-phase accidents. Full-ph...

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Problems solved by technology

[0003] The main purpose of the present invention is to provide a non-full-phase judgment method of a circuit breaker based on the rate of change of the fundamental voltage amplitude on both sides. The problem that the criterion cannot be identified. In addition, since there is no need to judge the three-phase inconsistent contacts of the circuit breaker, it also solves the non-full-phase discrimination problem of the three-phase linkage circuit breaker

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