Analysis and design of a zero voltage switching dc-to-ac inverter

In this paper, we present the steady state analysis and design for a dc-to-ac converter with zero-voltage-switching (ZVS) and output isolation. It is a current fed converter having variable frequency control to obtain a symmetrical regulated ac output. Two switches operate 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, shape and frequency of the output ac voltage. State space equations representing the steady state modes of operations are presented and basic circuit operation is discussed. Input and output characteristic curves are derived. Based on these curves, a design procedure with a specific example supported by simulation results is presented.