PUBLICATIONS

 This paper presents a method for lifetime extension of a two-level inverter with a reduction in the DC-link ripple current and power module temperature. The reliability of inverters has been widely explored at the device and inverter levels based on the physics of failure analysis. Switching module and capacitor failures account for more than 50% of inverter system failures. The failures of these components occur owing to the accumulated thermomechanical damage caused by power loss and thermal stress. This study analyzes the power loss and thermal stress by modeling the switching modules. The proposed method suppresses the thermal stress of the switch module by applying discontinuous PWM (DPWM) to reduce power loss. In addition, a phase-shifting scheme is applied to reduce the ripple current, which affects the loss and temperature of the DC-link capacitor. The feasibility of the proposed thermal reduction method is verified through simulations and experiments.