Research on Partial Discharge Signal Propagation Characteristics of UHV Core Reactor and Optimization of Measuring Points on Oil Tank Wall

As the core hub of reactive power compensation in ultra‐high voltage (UHV) power grids, UHV core reactors require accurate insulation monitoring to ensure grid safety. Aiming at the bottleneck of single‐signal optimization in existing partial discharge (PD) monitoring, this paper proposes a PD signal propagation analysis and measuring point optimization method for UHV core reactors. First, a multi‐physics coupling model is built via finite element theory to reveal the propagation mechanisms of PD ultrasonic and UHF electromagnetic signals in the reactor's complex internal medium. Based on their spatial attenuation laws, the tank surface is meshed, and a correlation mapping model between internal PD zones and tank partitions is established, clarifying signal paths and attenuation rules in key components. Then, correlation coefficients are calculated to quantify the sensitivity of each partition to PD signals, and a standard normalization method is introduced to eliminate fusion deviation from dimensional differences. Finally, optimal monitoring points are selected for efficient PD signal collection. This research reveals PD signal propagation characteristics, optimizes tank monitoring points, and improves the monitoring system's accuracy for early PD faults, providing theoretical support for UHV reactor condition assessment. © 2026 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.