Theoretical and Applied Review of Infrared Imaging Technology in High-Voltage Bushing Fault Diagnosis

High-voltage bushings constitute critical yet failure-prone components in power systems, where faults such as material aging, internal oil deficiency, moisture ingress, and poor connections typically manifest as abnormal heating detectable through infrared (IR) thermography. This comprehensive review examines IR imaging technology for bushing fault diagnosis, first analyzing characteristic temperature rise patterns of three primary faults—poor contact at terminals, abnormal oil levels, and excessive dielectric loss—via finite element simulations (COMSOL Multiphysics), revealing distinct thermal signatures that validate IR’s diagnostic efficacy. The study further surveys current IR-based methodologies, emphasizing a two-step machine-intelligent approach involving fault-region isolation through image segmentation followed by classification using extracted features. Despite advancements, persistent challenges encompass limited detection accuracy, inherent IR limitations in identifying internal faults, and processing complexities in intricate substation environments. Future directions advocate integrating IR with complementary techniques—including UV imaging, acoustic detection, and chemical analysis—within digital twin frameworks to enable multidimensional cross-verification, thereby advancing predictive, proactive, and intelligent maintenance strategies for bushings in smart grids.