Nondestructive evaluation method for high-frequency electrical parameters of power transmission cables and accessories

Abstract

The invention discloses a nondestructive evaluation method for the high-frequency electrical parameters of a power transmission cable and the accessories, which comprises a vector fitting process anda parameter optimization process, and specifically comprises the following steps of S1, carrying out vector fitting on a frequency domain model of the cable, and providing a lumped parameter equivalent circuit model to obtain parameters of a circuit model to be optimized; and S2, during a parameter optimization process, firstly injecting an excitation pulse source at the head end of the cable to obtain an experimental measurement waveform, and secondly, optimizing the circuit model parameters preliminarily proposed in the step S1 by adopting a simulated annealing algorithm in combination withthe experimental measurement waveform to realize the multi-parameter identification. According to the present invention, by adopting a series of algorithms and technologies of nondestructive pulse signal excitation, high-frequency circuit modeling and analysis and circuit element multi-parameter identification, the nondestructive evaluation of the high-frequency electrical parameters of the powertransmission cable and the accessories is achieved, and the method has important significance for accurately evaluating the changes of time and amplitude of a traveling wave head and improving the positioning precision.

Description

technical field [0001] The invention relates to the field of non-destructive evaluation methods, in particular to a non-destructive evaluation method for high-frequency electrical parameters of power transmission cables and accessories. Background technique [0002] The propagation of the fault pulse waveform in the complex cable line and the reflection at different positions have different characteristics; when the line topology is known, when the traveling wave of the high-voltage cable propagates along the line, the wave impedance of the cable itself remains unchanged. When the traveling wave propagates to When the line joint or the connection point with other equipment, the circuit parameters change suddenly, and the wave impedance also changes accordingly. Refinement is the basis for establishing an accurate analysis model; and the establishment of accurate distribution parameters for each of the above parts needs to be determined in consideration of factors such as str...

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Problems solved by technology

[0005] The present invention provides a non-destructive evaluation method for high-frequency electrical parameters of power transmission cables and accessories in order to overcome the defect of low precision in the non-destructive evaluation of high-frequency electrical parameters of power transmission cables and accessories in the prior art

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