PD Signal Detection Model Based on Multiscale Simulation of EM Generation and Transmission

Nowadays, the digital twin method has been gradually applied to power equipment condition monitoring. Since a main fundamental part of the digital twin is a simulation process with better fitting for the real one, this article is devoted to building up a partial discharge (PD) detection model to simulate the generation and transmission of electromagnetic (EM) wave signals caused by PDs, especially those inside the void defects. This model combines the micro-discharge process with the transmission process inside certain geometry structures. Specifically, two commonly used methods are applied to simulate the processes correspondingly. The dielectric barrier discharge (DBD) model is used for the PD simulation inside void defects, while the finite-difference time-domain (FDTD) method is for the EM signal transmission process. The pulsed discharge current can be obtained during the simulation of DBD, which can function as the excitation source of the transmission process solved by FDTD. According to the PD detection model, the influences on the simulation results are discussed, including the impact on the discharge current caused by coefficient variation and the impact on the transmission process caused by the power equipment geometry structure and materials. As mentioned above, this article is aimed at building a direct relationship between the observed EM signal and the micro-discharge process, which reveals the physical process of PD signal measurement in virtual space that can provide more features for PD pattern recognition or noise elimination, and further the mechanism and theoretical analysis support for digital twin application.