Analysis and design of a parallel resonant converter including the effect of high-frequency transformer

A high-frequency-link DC-DC parallel resonant converter operating above resonance is analyzed, including the effect of a high-frequency transformer, using the state-space approach. Steady-state solutions are derived and are used to obtain the design curves. A method of obtaining the optimum operating point under certain constraints is outlined and used to develop a simple design procedure. The analysis shows that the inclusion of a high-frequency transformer results in the introduction of a new mode of operation in between the two general steady-state modes. Experimental results obtained with a MOSFET-based parallel resonant converter for three different transformer turns ratios are presented to support the theory