Analysis and design of a zero voltage switching DC-to-AC inverter

In this paper, the authors present a simplified steady state analysis and design for a DC-to-AC inverter with zero-voltage-switching (ZVS) and output isolation. It is a current-fed power converter having variable frequency control to obtain a symmetrical regulated AC output. Two switches operating in complementary fashion to control the operation of the converter and provide transformer core resetting. The resonance between the parasitic capacitances, transformer magnetizing inductance, and output side inductor allow ZVS for both switches, hence, reducing switching losses. The output has an LCC resonant tank circuit which controls the output power flow, and sets the frequency of the output AC voltage. Using simplified steady-state analysis, input and output characteristic curves are derived for different transformer ratios. Based on these curves, a design procedure with a specific example supported by simulation results is presented.