Exact analysis and design of zero voltage switching operation for class E inverter with circuit components varying

In this study, an exact circuit model for the class E inverter is proposed to analyse the circuit behaviour in frequency domain without mathematical assumptions. Through this model, a close form formula is proposed to solve the load current and drain-source end voltage of metal oxide semiconductor field effect transistor at switching instants in steady-state instead of complicated numerical iteration. With these current and voltage at switching instants, the load current can be expressed with exact function and evaluated. By means of the proposed formula and current expression, the optimal and suboptimal conditions for the zero voltage switching (ZVS) operation have been expressed in terms of the shifting angle of load current with respect to drain-source voltage. Further, the ZVS and non-ZVS operation regions can be marked via calculating the shifting angle and optimal shifting angle, which are proposed in the study. To demonstrate the proposed formulas and ZVS conditions, some examples are given to examine the analysis and ZVS drifting behaviour with comparing of calculation, simulation and experiment. Good agreements from the illustrated examples have given the verification of the analysis and design for the class E inverter.