Method and system for locating partial discharge of electrical equipment

Abstract

A method for locating partial discharge of electrical equipment is used for detecting and locating partial discharge of the electrical equipment. The technical scheme includes the steps: firstly, using three ultrasonic array sensors to receive partial discharge ultrasonic signals at different positions of the electrical equipment and forming an array model; then, converting broadband signals received by the three ultrasonic array sensors into narrow-band signals by applying a TLS (transport layer security)-based broadband focus algorithm, and obtaining azimuth information of partial discharge sources according to a narrow-band direction-finding algorithm combining the phase matching principle and cloud optimization search; and finally, determining specific positions of electrical equipment partial discharge by means of a partial discharge source location algorithm based on global optimization search of a modified genetic algorithm. The invention simultaneously provides an improved system for locating partial discharge. Compared with a traditional method for locating partial discharge, the method has the advantages of small calculation amount, high direction-finding precision, accuracy in location, high convergence rate and the like, and the system for locating partial discharge is simple in structure, low in cost and high in location precision.

Description

technical field [0001] The invention relates to a method and a detection system for detecting the internal partial discharge position of electrical equipment, belonging to the detection technical field. Background technique [0002] The detection and precise location of partial discharge are of great significance for timely discovery of latent insulation defects inside electrical equipment and prevention of accidents. [0003] There are many detection methods for partial discharge. Ultrasonic method has been widely used because of its simple principle and convenient positioning. However, due to the complex propagation of ultrasonic waves inside the transformer, it is difficult for ordinary ultrasonic sensors to detect ultrasonic signals in some cases. Therefore, in related studies, ultrasonic array sensors with strong interference suppression capabilities and high spatial resolution capabilities are used instead of single ultrasonic sensors. Array signal processing technolo...

AI Technical Summary

Problems solved by technology

However, these methods still have problems such as insufficient precision and error amplification.

[0009] (2) Insufficiency in denoising method of partial discharge ultrasonic array signal

[0010] The environment in which electrical equipment operates is extremely complex, and there is strong background noise around. Because the partial discharge ultrasonic signal is very weak, it is often buried in the strong background noise, which greatly reduces the accuracy of partial discharge detection and even causes detection failure.

Traditional denoising methods have a good denoising effect on single-channel and single-array ultrasonic signals. However, for partial discharge ultrasonic array positioning methods for electrical equipment, there is currently a lack of a mature denoising method. If the traditional denoising method is used method, the phase difference information of the array signal is seriously lost, which is the key data for PD positioning

[0011] (3) Deficiencies in the design of partial discharge ultrasonic array sensors

[0012] Most of the ultrasonic array sensors used in existing positioning methods use planar square arrays and linear array sensors. Planar square array sensors can obtain two-dimensional azimuth and elevation angle information of PD sources, but due to the large number of array elements, the cost is high ; The principle of the linear array sensor is simple. While ensuring a certain direction-finding accuracy, it can reduce redundant array elements and greatly reduce the cost. However, it can only obtain the one-dimensional orientation information of the partial discharge source, ignoring the airspace characteristics of the signal.

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