Analyzing the Influence of Skin Effects on PWM-Induced Partial Discharge at Elevated Temperatures and Reduced Pressures

Pulse Width Modulation (PWM) signals are crucial in modern power electronics, offering enhanced control and efficiency in high-power applications such as motors, inverters, and renewable energy systems. However, the high switching frequencies associated with PWM signals lead to significant challenges, including pronounced skin effects. These effects concentrate current near conductor surfaces, increasing localized heating and insulation stress, which can contribute to partial discharge (PD). This study examines how elevated temperatures and reduced pressures amplify the skin effect, impacting PD inception voltage (PDIV) and magnitude. By analyzing numerical simulations in COMSOL Multiphysics and real-world experimental validation, we demonstrate how reducing the slew rate of PWM signals can mitigate PD. A lower slew rate reduces the severity of the skin effect, thereby minimizing electric field stress at insulation interfaces. The results highlight the importance of controlling PWM signal characteristics as a means to enhance insulation longevity and system reliability in extreme environments such as aerospace and high-altitude applications.