采用高阶累积量的环网柜局部放电在线检测

根据环网柜的绝缘缺陷,设计3种典型的局部放电模型,搭建局部放电试验平台.借助射频电流传感器获取局部放电混合信号,经过放大和高速A/D采样后,将信号送入微型计算机进行处理.采用四阶累积量作为局部放电特征量,抑制随机噪声干扰,提高信噪比.通过Otsu算法确定检测判据,实现局部放电的在线检测.将检测算法移植到现场可编程门阵列(FPGA)上,研发环网柜局部放电在线检测装置.试验结果表明:该装置能够适应较强的噪声环境,且具有良好的实时检测效果.

On-Line Partial Discharge Detection of Ring Main Unit Using Higher-Order Cumulants

According to the insulation defects of ring main unit, three kinds of typical partial discharge(PD)models were designed, and the PD test platform was built. With used radio frequency current sensor to obtain the mixed PD signals, and the signals were sent to a microcomputer for processing after amplification and high-speed A/D sampling. Then, fourth-order cumulants were used as PD characteristic to suppress the random noise. Meanwhile, the signal to noise ratio(SNR)was improved. Detection criterion was determined by the Otsu algorithm in order to realize the on-line PD detection. The detection algorithm was transplanted to the field-programmable gated array(FPGA)and an on-line PD detection device for ring main unit was developed. The experimental results showed that the device could adapt to the strong noise environment, and had good effects of real-time detection.