基于优化小波阈值函数的高压电缆局放信号消噪研究

Research on Denoising of High Voltage Cable Partial Discharge Signals Based on Optimized Wavelet Threshold Function

为了得到高压电缆准确可靠的局放信号,需要从监测到的信号中滤除白噪声、混杂的随机噪声等,为此设计了基于优化小波阈值函数的局放信号消噪法。该算法在小波变换阈值去噪的基础上进行优化,优化后的阈值和阈值函数在不同的分解层数下,具有较好的自适应能力,经计算机仿真、实验室模拟、现场测试实验证明,该优化后的阈值函数消噪法具有有效性与可行性,该方法不仅能准确地识别局放信号,而且能有效提高高压电缆在线绝缘监测的准确性。

In order to obtain accurate and reliable partial discharge signal of high voltage cable,it is necessary to filter out white noise and mixed random noise from the monitored signals.Therefore,this paper designs the denoising method based on the optimized wavelet threshold function.The algorithm is optimized on the basis of wavelet transform threshold denoising.The optimized threshold and threshold function have good adaptability under different decomposition layers.The algorithm is proved to be effective by computer simulation,laboratory simulation and field test.The experimental results show the effectiveness and feasibility of the optimized threshold function denoising.Based on the optimized wavelet threshold function,the pratial discharge signal denoising method can not only accurately identify the pratial discharge signal,but also effectively improve the accuracy of high-voltage cable on-line insulation monitoring.