AC power supply based on half-bridge resonant converters

AC power supplies with back-up capabilities often require galvanic isolation between the input, the output, and the battery. A significant reduction in the size of the input and the output filters, the transformer and magnetics is achieved by increasing the switching frequency. However, in hard switched converters, this also increases the switching losses. To reduce the switching losses this paper proposes an AC power supply topology with back-up capabilities based on the series parallel half-bridge resonant converter. The main features of the proposed configuration includes: (i) isolation with a single transformer; (ii) zero voltage switching in the high frequency converters; and (iii) unity input power factor. Operating principles and static characteristics of the converter are derived. Finally, proof-of-concept for the proposed converter is experimentally verified