Partial discharge localization method based on propagation delay compensation of electro-acoustic joint detection signal

Abstract

The invention discloses a partial discharge localization method based on electro-acoustic joint detection signal propagation delay compensation. The method firstly samples and extracts partial discharge ultra-high frequency electromagnetic waves and ultrasonic acoustic signals, and obtains electromagnetic wave pulses and ultrasonic waves generated by partial discharge sources. Acoustic pulse signal; then extract the propagation delay characteristics of the two signals respectively; take the propagation delay characteristic value of the electromagnetic wave signal as a reference to obtain the relative propagation delay of the ultrasonic signal, and carry out the relative propagation delay under the metal boundary condition. Correction and compensation; then calculate the distance between the partial discharge source and the ultrasonic sensor; repeat the sampling to calculate the distance between the partial discharge source and a single ultrasonic sensor, and use the arithmetic mean value of the distance as the final determined distance between the partial discharge source and the ultrasonic sensor; finally combine The electrical arrangement in the cabinet determines the specific location of the partial discharge source. The positioning method of the present invention can more accurately reflect the exact position of the partial discharge source of the equipment.

Description

technical field [0001] The invention belongs to the technical field of partial discharge detection, and in particular relates to a partial discharge localization method for a high-voltage switch cabinet 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 caused by electrical, thermal and chemical factors, the electrical insulation strength is reduced, partial discharge occurs, and even sudden insulation breakdown occurs. Partial discharge is a symptom and manifestation of equipment insulation deterioration. By performing partial discharge detection on switchgear equipment, you can know whether there is partial discharge in the cabinet, the specific location of partial discharge, and the type and amount of partial discharge, so as to evaluate the switchgear The degree of equipment insulation deterioration and the degree o...

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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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