Ultrasonic automatic detection system for self-healing discharge of self-healing parallel capacitor and ultrasonic automatic detection method

Abstract

The invention discloses an ultrasonic automatic detection system for self-healing discharge of a self-healing parallel capacitor and an ultrasonic automatic detection method. The method comprises thesteps of picking up an ultrasonic signal generated by the self-healing discharge by adopting an acoustic emission sensor; amplifying the weak ultrasonic signal of the self-healing discharge by using apre-amplifier, and performing analog filtering on the signal through a band-pass filtering module; transmitting the signal to an upper computer by using a high-resolution A/D acquisition board card;processing and identifying the ultrasonic signal by the upper computer; judging the number of self-healing discharge times of the capacitor to be detected, judging the current self-healing discharge detection stage of the self-healing parallel capacitor according to the direct-current power supply output voltage value acquired by the voltage sensor in real time; and finally giving a detection report. The method is safe, portable and easy to operate, the discharging process is judged by detecting the ultrasonic signal generated by self-healing discharge of the capacitor, the method is suitablefor self-healing discharging detection occasions of the self-healing parallel capacitor, and a reliable and accurate detection means is provided for the self-healing parallel capacitor for an alternating-current power system.

Description

technical field [0001] The invention relates to the field of ultrasonic technology and performance detection of self-healing parallel capacitors used in AC power systems, in particular to an ultrasonic automatic detection system and method for self-healing discharge of self-healing parallel capacitors. Background technique [0002] The self-healing capacitor uses a single-layer polypropylene film as the medium, and a thin layer of metal is evaporated on the surface as the conductive electrode. When an excessively high voltage is applied, the weak point of the polypropylene film is broken down, the impedance of the breakdown point is significantly reduced, and the current density flowing through it increases sharply, causing the metallized coating to generate high heat, and the metal conductor around the breakdown point evaporates rapidly. Dispersion, forming a blank area of ​​metal plating, and the breakdown point automatically restores insulation. [0003] The above proces...

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Problems solved by technology

The above methods all need to judge whether the self-healing breakdown phenomenon occurs m

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