Zero voltage switching series resonant based DC-AC converter

This paper describes and analyses an isolated single-phase bidirectional DC-to-AC converter for uninterruptible power supply systems. The main achievements of the proposed converter are: (i) operation with zero voltage switching at all load conditions; (ii) inherent protection against short circuits in the load; (iii) high quality output waveform; (iv) isolation between the DC and AC sides using high frequency transformer; and (v) the leakage induction of the transformer is used as part of the series resonant inductor. The operating principles of the DC-to-AC converter are described and the relation among the power circuit variables are derived. Experimental results, which substantiate the analysis and demonstrate the feasibility of the DC-to-AC converter, are given