Study on Dynamic Adjustment Method for Dead Time of Inverters in EV-WPT System Based on Mutual Inductance Changes

During the energy conversion process of high-frequency inverters, the power switches in the complementary branch need to have a certain dead time interval to avoid the occurrence of shoot-through phenomenon. However, setting the dead time too long will cause the polarity of the inverter output current to reverse during the dead time, thereby causing the inverter output voltage to undergo voltage polarity reversal (VPR) prematurely. The dead-time effect of the inverter will affect the operation of the entire electric vehicle wireless power transmission (EV - WPT) system, such as increased switch losses, severe heating of power devices, decreased system output power, and reduced efficiency. This article proposes a dead time dynamic adjustment method for the input impedance characteristics of EV - WPT under changing mutual inductance conditions, in order to suppress the VPR phenomenon of inverters. The correctness of the proposed method has been verified through simulation, effectively suppressing the dead-time effect of the inverter and improving the working stability of the system.