Analysis of the Impact of Partial Discharge Locations on Ultra-High Frequency Signal Propagation Characteristics

Transformers are critical devices for the functioning of power grids. Partial discharge, the leading cause of insulation failure, has consistently been a central focus in transformer fault detection and the assurance of safe operation. Among the various methods for detecting partial discharges, ultra-high frequency (UHF) is widely employed as measured quantities due to its outstanding sensitivity and strong resistance to interference. However, as UHF signals propagate within the transformer, internal components can easily obstruct them, leading to alterations in their propagation characteristics. These changes can hinder effective fault detection. Therefore, it is crucial to consider how the placement of the discharge source influences UHF signal transmission. In this study, an optimized model based on a real 110 kV device is developed through the Finite-Difference Time-Domain (FDTD) method to examine the dissemination of UHF waves generated by partial discharges. To evaluate the impact of different discharge source locations, simulations are conducted with examples of partial discharges occurring between the winding and the tank wall, as well as between windings. Drawing from the findings, the research investigates the propagation dynamics of UHF electromagnetic signals and analyzes how the discharge source location influences these characteristics.