A method and device for identifying cable partial discharge signals based on s-transform

Abstract

The embodiment of the present invention discloses a cable partial discharge signal identification method and device based on S-transformation, which is used to solve the problem that the waveform time difference method is usually used in the current location of the partial discharge signal source of the power cable, and the identification accuracy is low and the required identification time is too long. Long technical question. The method in the embodiment of the present invention includes: performing S-transformation on the acquired partial discharge signal from a known source to obtain a complex time-frequency matrix; performing modulus on the complex time-frequency matrix to obtain a modulus matrix, and performing singular value decomposition on the modulus matrix to obtain The singular value sequence of the modulus matrix; the singular value sequence is divided into at least two intervals, the ratio of the Shannon entropy of the singular value in each interval to the Shannon entropy of the singular value sequence is calculated, and the partial discharge signal eigenvector is established with the ratio Partial discharge signal feature sample library and build a support vector machine model; input the feature vector of the partial discharge signal to be identified into the support vector machine model to obtain the source of the partial discharge signal to be identified.

Description

Technical field [0001] The invention relates to the technical field of cable partial discharge online monitoring, and in particular to a cable partial discharge signal identification method and device based on S transformation. Background technique [0002] With the rapid and continuous development of the power system, the length of the laying loop of the power cable has been steadily increased, and it has been widely used in cities. However, with the increasing power load and voltage level, insulation problems caused by partial defects in cables pose a great threat to power supply quality and social economy. In order to monitor the insulation status of the cable and discover its local defects in time, so as to prevent the occurrence of cable operation accidents and ensure the reliability of power grid operation, it is necessary to detect the local defects of the cable. [0003] In the on-line monitoring of cable partial discharge, the detected partial discharge signal may come fr...

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Problems solved by technology

[0006] The embodiment of the present invention provides a cable partial discharge signal identification method and device based on S-transformation, which solves the problem that the power industry usually uses the waveform time difference method to locate the source of the partial discharge signal of the power cable. When the power cable line is too long, the recognition accuracy is greatly reduced and the required recognition time is too long

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