Insulation Degradation Analysis on Electrical Machines Under Fast and Repetitive Voltage Pulses: A Review

The insulation degradation in electrical machines is a critical concern, especially under the influence of modern power electronics-based variable frequency drives. Hence, it increases the occurrence of fast and repetitive voltage pulses on the insulation system. This review article offers a comprehensive perspective on the mechanisms and factors contributing to insulation degradation under these conditions. Review on two decades of research and development in the field, this article synthesizes findings from key studies, highlighting critical degradation processes, such as partial discharges, electrical treeing, and thermomechanical stresses are the highlights of this article. Additionally, it discusses recent advancements in mitigation strategies and design improvements aimed at enhancing insulation resilience. The insights presented herein are pivotal for improving the reliability and extending the operational lifespan of electrical machines in modern industrial applications.