电缆接头局部放电在线检测系统的设计

Design on On-Line Detection System of Partial Discharge in Cable Joints

针对电缆接头绝缘故障难以检测的问题,设计一种基于高频电流法的电缆接头局部放电在线检测系统。系统以DSP+FPGA为核心,通过FPGA采集安装在电缆接头接地线上高频电流互感器(HFCT)耦合的局部放电信号,利用DSP芯片,编写FFT和小波变换程序对局部放电信号中窄带干扰和白噪声分别进行噪声抑制,实现对电缆接头局部放电信号的在线检测。最后,将示波器采集信号与MATLAB降噪处理结果分别与在线检测系统进行比较,结果具有一致性,证明了所设计系统的有效性。

In order to solve the problem that the insulation fault of the cable joint is difficult to detect, the partial discharge on-line detection system for the cable joint based on the high-frequency current method is designed.The DSP and FPGA are taken as the core to collect the partial discharge signal coupled with high frequency current transformer(HFCT) installed on the ground wire of the cable connector through FPGA.The DSP is used to compile FFT and wavelet transform programs to suppress the white noise and narrow-band interference of the partial discharge signals, which can achieve on-line detection of partial discharge signals.Finally, the oscilloscope signal and MATLAB noise reduction processing results are compared with the on-line detection system.The comparison results are consistance, which can prove the effectiveness of this system.