High-voltage power modules in converter equipment are subjected to long-term combined stresses
including high electric fields
high temperatures
and high dU/dt
making packaging insulation failure a critical issue for reliable operation. This paper reviews the failure mechanisms and coordinated regulation of electro-thermal performance in silicone-gel packaging insulation and its gel-solid interfaces
as well as electro-thermal coordinated regulation. The typical packaging structures of high-voltage power modules and insulation condition sensing methods are summarized. Then
the material properties and initial insulation state of silicone-gel packaging insulation are reviewed
followed by an analysis of high-temperature degradation and interfacial deterioration
as well as the aging-induced evolution of the electrical
thermal
and mechanical properties of insulating materials. The development mechanisms of partial discharge
gel-solid interfacial discharge
and electrical treeing under coupled multi-stress conditions are further discussed. On this basis
recent advances in local electric-field regulation
thermal-conductivity enhancement
and electro-thermal performance optimization are comparatively analyzed. Finally
future research directions are proposed in terms of quantitative failure-path modeling
multi-parameter condition sensing and lifetime assessment
electro-thermal coordinated design
and evaluation under realistic service conditions. This review provides reference for understanding insulation failure mechanisms
optimizing packaging materials
and improving the reliability design of packaging insulation in high-voltage power modules.