Study on the Electromagnetic Characteristics of two Different Types of Partial Discharge at the Initial Stage

In the realm of partial discharge (PD), the emission of an electromagnetic wave signal can be observed. Detecting this signal is crucial to ascertain the occurrence of partial discharge. However, during the early stages, the electromagnetic wave signal is feeble, and it can be submerged by other interference electromagnetic waves. To address this challenge, surface and tip discharge models are employed to measure the frequency of the electromagnetic wave signal during the initial stages of partial discharge. Notably, the frequency centers of the tip discharge signal are 50MHz and 600MHz, whereas the frequency centers of the surface discharge signal are 30MHz and 800MHz. Based on the primary frequency range of the signal, the selection frequency range of the filter is designed accordingly. Specifically, the tip discharge bandpass is set at 400MHz-800MHz, while the surface discharge bandpass is set at 600MHz-1GHz. The filtered UHF method noise signal can significantly reduce the noise, enabling the identification of PD signal with greater clarity. The research outcomes serve as a foundation for the application of UHF method in PD detection.