Circuit breaker state online diagnosis method and system based on PMU (Phasor Measurement Unit) data

Abstract

The invention discloses a circuit breaker state online diagnosis method and a system based on PMU (Phasor Measurement Unit) data, which relate to the technical field of power system circuit breaker protection. A grey target theory is introduced to circuit breaker state diagnosis, the irrationality of adopting a weight average algorithm to calculate the approaching degree by the traditional grey target theory is improved, a hierarchy-entropy weight combined weight calculation method is put forward, the influence weight of each index for an evaluation result is solved, advantages of the two aretaken to remedy disadvantages of each, both subjective and objective factors are considered, defects of a single assignment method are avoided, weight determination is thus more rational, the safe andreliable operation is very important for improving reliable power supply of the power grid, and a basis is laid for realizing state maintenance for the circuit breaker.

Description

Technical field [0001] The invention relates to the technical field of power system open circuit protection, in particular to a method and system for on-line diagnosis of circuit breaker states based on PMU quantities. Background technique [0002] Phasor Measurement Unit (PMU) is a device used to measure and output synchronized phasor and perform dynamic recording. The PMU in the power system synchronously collects sub-second analog voltage and current signals from GPS, obtains the amplitude and phase angle of the voltage and current signals, and transmits them to the data concentrator in the dispatch center, where the entire power grid can be obtained The synchronized phasors are used for real-time monitoring, protection and control, and are widely used in all aspects of the power system wide-area measurement system. How to use PMU data to monitor the state of circuit breakers used on a large scale in the power grid plays a very important role. [0003] However, the circuit bre...

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Problems solved by technology

[0003] However, for the circuit breaker on-line monitoring and diagnosis system, various sensors are generally installed on the circuit breaker body, and the circuit breaker diagnosis is realized through the data collected by various sensors. This method has the disadvantages of high installation cost and complicated diagnostic methods.

In the current published prior art, there is no online evaluation of circuit breaker operating status through the online extraction of data from the power system PMU, and no modification of the power system is required based on the PMU data

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