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

The insulation degradation in electrical machines are a critical concern, especially under the influence of modern power electronics based variable frequency drives. Hence, it increases occurrence of fast and repetitive voltage pulses on the insulation system. This review paper 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, the paper synthesizes findings from key studies, highlighting critical degradation processes such as partial discharges, electrical treeing, and thermo-mechanical stresses are the highlights of this paper. 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.