Simulation Analysis on Electro-Thermal Field Distribution Characteristics of 36 kV-26 kA Bushings Under Varying Load Ratios

Low-voltage high-current bushings endure substantially greater operational currents compared to conventional transformer bushings, resulting in distinct electrothermal characteristics in their temperature and electric field distributions. This necessitates a systematic analysis of their electro-thermal field patterns under varying current load ratios. This study investigates a full-scale 36 kV - 26 kA resin-impregnated paper (RIP)- bushing prototype, establishing a coupled electrothermal simulation model. Results reveal pronounced asymmetric thermal distribution characteristics in high-current bushings across load conditions. While environmental factors and selfgenerated heat differentially dominate temperature profiles at varying load ratios, electric field distributions remain loadinvariant due to the permittivity-temperature decoupling. These findings provide critical insights for developing operational condition assessment and risk early-warning methods.