Simulation analysis on the propagation characteristics of electromagnetic wave generated by partial discharges in the power transformer

The analysis on the propagation characteristics of electromagnetic (EM) wave generated by partial discharges (PD) is expected to be made, because it is extremely important not only for setting the optimum sensor position and improving the sensitivity of detection but also for establishing a method of calibrating electrical charges and conducting a high-accuracy location identification of the PD source. In this paper, based on actual parameters of the 110kV power transformer, the simulation model was built by the CST Microwave Studio. The propagation characteristics of EM wave in the power transformer was analyzed, and the detection scheme of EM waves around the 35kV and 10kV bushings was put forward. The simulation results show that the radiated field amplitude is exponentially decreased with the increase of distance between PD sources and probes, and the drastic attenuation of radiated field amplitude is caused by the windings and core. The radiated field amplitude is exponentially decreased with the increase of current pulse's width and has a linear relationship with current pulse's amplitude. Beside the 35kV and 10kV bushings, the EM wave can be effectively detected, and the optimal location to install the sensors is determined.