A Switching Frequency Selection Method for Single-phase PWM Rectifier Considering Lifespan and THD

Single-phase PWM rectifier is essential to the electric traction system. The power device, as one of the most vulnerable components in the rectifier, has a significant influence on the reliability of the system. This paper presents a switching frequency selection method for a single-phase PWM rectifier considering lifespan and current THD to prolong the service life. Firstly, the influence of switching frequency on device unit damage and current THD is investigated, and they are normalized to balance the effect level of both. Then, a cost function is defined to select the optimal switching frequency considering the unit damage and THD, where the weighting factors are different at various stages of the service life. Finally, the simulation result is presented to validate the effectiveness of the proposed method.