Research on Online Calculation Method of Partial Discharge of Power Cable

Aiming at the problem that the propagation of partial discharge(PD) signal on power cable has the characteristics of fast attenuation, resulting in large measurement error of PD, a calculation method of PD based on digital filter is proposed. The simulation model of three core power cable is established by ATP-EMTP, and the attenuation law of PD signal along the line is obtained. Through the MATLAB spectrum analysis tool, the spectrum characteristics of PD signals in different positions are obtained. According to the spectrum characteristics, FIR digital filter is designed to filter out the high-frequency components, and the low-frequency components are used to calculate the PD. The simulation results show that the proposed method can significantly improve the measurement accuracy of PD and meet the requirements of online calculation of partial discharge.