Closed loop control of a pulsed series parallel resonant converter with current doubler

In this paper a series-parallel resonant converter with a current doubler at the output is designed to produce a pulsed voltage to feed an electrochemical waste water treatment cell. The small signal model of the converter is derived to design the compensators of a cascaded control loop with an inner current and an outer voltage loop. The design procedure of the compensators in the control loop is also demonstrated. To avoid any measurements at the electrochemical cell the output voltage and current are estimated through the measured signals on the high voltage, low current primary side. Simulation and experimental results are given to validate the operation of the power supply under pulsed operation.