Partial discharge positioning method based on electroacoustic joint detection signal propagation time delay compensation

Abstract

The invention discloses a partial discharge positioning method based on electroacoustic joint detection signal propagation time delay compensation. The method comprises the steps of: carrying out sampling and extraction on partial discharge ultrahigh frequency electromagnetic waves and ultrasonic acoustic signals, and obtaining electromagnetic wave pulses and sound pulse signals generated by a partial discharge source; respectively extracting propagation time delay characteristics of the two kinds of signals; taking the propagation time delay characteristic value of the electromagnetic wave signals as a reference datum, obtaining the relative propagation time delay of the ultrasonic wave signals, and carrying out correction compensation on the relative propagation time delay under a metal boundary condition; calculating the distance between the partial discharge source and an ultrasonic sensor; repeatedly sampling for multiple times to calculate the distance between the partial discharge source and the single ultrasonic sensor, and taking the arithmetic mean value of the distance as the finally judged distance between the partial discharge source and the ultrasonic sensor; and finally, determining the specific position of the partial discharge source on the basis of electrical arrangement in a cabinet. According to the positioning method, the accurate position of the partial discharge source of equipment can be embodied more accurately.

Description

technical field [0001] The invention belongs to the technical field of partial discharge detection, and in particular relates to a method for locating partial discharge of a high-voltage switchgear based on electro-acoustic joint detection and signal propagation delay compensation. Background technique [0002] In the long-term operation of high-voltage power switchgear, there must be insulation defects due to electrical, thermal, and chemical factors, the electrical insulation strength is reduced, partial discharge occurs, and even sudden insulation breakdown occurs. Partial discharge is a sign and manifestation of equipment insulation degradation. Partial discharge detection of switchgear equipment can help you know whether there is partial discharge in the cabinet, the specific location of partial discharge, the type and discharge amount of partial discharge, and evaluate the switchgear. The degree of deterioration of equipment insulation and the degree of harm to operati...

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Problems solved by technology

However, for electrical equipment made of metal materials such as high-voltage switchgear, considering that the inner wall of the switchgear is surrounded by metal plates, there are also a large number of metal connectors and partitions in the cabinet, so the ultra-high frequency electromagnetic wave signal and ultrasonic signal from the local discharge source in the cabinet In the process of diffusion and propagation, reflection and refraction of this metal part will inevitably occur, resulting in a certain signal multipath fading. Therefore, when determining the relative time difference of the electroacoustic signal, it is necessary to control the transmission of electromagnetic waves and ultrasonic waves by the metal parts in the cabinet. Considering the impact, how to properly correct and compensate the propagation delay of the electro-acoustic signal is the key and difficult issue for realizing precise positioning.

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