A method for detecting partial discharge of high-voltage switchgear

Abstract

The invention provides a method for detecting partial discharge in a high-voltage switchgear, including a plurality of ultrasonic sensors, a band-pass filter circuit, a pre-amplifier circuit, a post-amplifier circuit and a controller, an output end of the ultrasonic sensor and an input end of the band-pass filter circuit Electrically connected, the output end of the band-pass filter circuit is electrically connected to the input end of the pre-amplification circuit, the output end of the pre-amplification circuit is electrically connected to the input end of the post-amplification circuit, and the output end of the post-amplification circuit is electrically connected to the input end of the post-amplification circuit. The input end of the controller is electrically connected. The partial discharge detection circuit of the high-voltage switchgear provided by the present invention provides multiple input channels in the form of a matrix; multiple detection inputs are formed, and non-contact detection of partial discharge in the switchgear is realized through ultrasonic sensors at different positions.

Description

technical field [0001] The invention relates to the field of electric equipment, in particular to a method for detecting partial discharge of a high-voltage switch cabinet. Background technique [0002] High-voltage switchgear is generally used in the fields of power generation, transmission, distribution, power conversion, and consumption in power systems. It can play on-off, control, or protection functions. Its voltage level is between 3.6kV and 550kV, and it can be divided into high-voltage loads. Switches, high-voltage isolating switches and grounding and other types. In actual work, high-voltage switchgear often has the problem of partial discharge, which causes insulation performance to deteriorate, accelerates the insulation damage process, and increases the power consumption of the entire system. Therefore, it is very necessary to detect the partial discharge of the high voltage switchgear. [0003] The partial discharge of the switchgear will directly affect the ...

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Problems solved by technology

[0003] The partial discharge of the switchgear will directly affect the power generation efficiency and power supply security, and at the same time affect the safe and stable operation of the entire power system

Common partial discharge detection methods include ultra-high frequency detection method, transient low voltage method and pulse current detection method, etc. UHF detection method is to detect high-frequency electromagnetic waves within 0.5-3GHz excited by partial discharge. The type and severity of partial discharge can be judged by the amplitude and frequency characteristics, which can be detected without power failure and can effectively suppress background noise, but this method cannot accurately locate the fault location; the transient earth voltage method is referred to as TEV, and the TEV signal is detected by a special sensor , but this method is easily interfered by electromagnetic waves, and the reliability is not high; the pulse current detection method is generally used in the case of power failure; the above methods have some shortcomings

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