Vacuum degree monitoring method and device in high-voltage vacuum circuit breaker

Abstract

The invention discloses a vacuum degree monitoring method and device in a high-voltage vacuum circuit breaker. The method comprises the following steps: acquiring an electromagnetic wave signal of a to-be-monitored high-voltage vacuum circuit breaker and converting the electromagnetic wave signal into an electric signal; sequentially carrying out amplification processing, band-pass filtering processing and re-amplification processing on the converted electric signal; comparing the re-amplified electric signal with a set threshold value of a comparator, judging that the vacuum degree of the to-be-monitored high-voltage vacuum circuit breaker is reduced when the electric signal of which the amplitude is greater than the set threshold value of the comparator within set time reaches a set counter module value, taking the signal amplitude as a first parameter; taking the frequency of the pulse signals within a certain period of time as a second parameter, respectively setting thresholds forcomparison, and then judging the reduction degree of the vacuum degree in the vacuum arc-extinguishing chamber. According to the invention, the electromagnetic signals are used for real-time monitoring, and the amplitude and frequency of the pulse signals are used for parameters for judgement, so the accurate monitoring of the vacuum degree can be realized without contacting the arc extinguish chamber and changing the structure of the arc extinguish chamber.

Description

technical field [0001] The invention belongs to the technical field of electrical fault detection of high-voltage vacuum circuit breakers, and in particular relates to a vacuum degree monitoring method and device in high-voltage vacuum circuit breakers. Background technique [0002] Circuit breakers are important electrical control devices in power systems. Because SF6 has good thermochemical properties and strong electronegative properties, as well as excellent arc extinguishing and insulation properties, it is widely used in circuit breakers. But SF6 is a greenhouse gas and is listed as a restricted gas. People hope to find other media to replace SF6 in order to reduce the impact on the environment. Compared with SF6 circuit breakers, vacuum circuit breakers are small in size, good in breaking performance, long in service life (up to 30 years), and there is no risk of explosion, and the maintenance workload is small, so the development is rapid and the production volume ...

AI Technical Summary

Problems solved by technology

However, the existing online monitoring technology is not mature enough and has poor applicability

For example, the coupling capacitance method needs to place detection electrodes, and due to the formation of coupling capacitance, it poses a threat to the insulation of various parts of the circuit breaker; the built-in sensor method changes the internal structure of the arc extinguishing chamber, and the built-in vacuum sensor realizes online monitoring; the electro-optical measurement method uses some optical The components will change the optical properties in the electric field to achieve monitoring, but the optical components have poor working stability and high cost

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