Constant frequency controlled full-bridge LCC-type parallel resonant converter

A constant-frequency controlled full-bridge LCC-type parallel resonant converter is presented. By using a proper transformation on the state variables, the converter is analyzed by means of a two-dimensional state-plane diagram, which shows that the converter possesses three operation modes. Control characteristics and component stress curves are derived for only operation mode II. It is shown that operating that converter in operation mode II provides the desirable converter gains for a wide load range. In addition, these control characteristics curves reveal that the converter possesses better load regulation when compared to those of the second order full-bridge constant frequency controlled parallel resonant converter. A design example and computer simulation results are given to confirm the analytical work