LLC series resonant converter with PID controller for battery charging application

In this paper, the output voltage regulation of a halfbridge LLC series resonant DC-DC converter using a PID controller in feedback loop for the battery charging application is presented. The PID controller is used to adjust the frequency of gate pulses generated by the voltage controlled oscillator (VCO) for deriving the MOSFETs to regulate the output voltage. The converter is implemented using MATLAB Simulink environment for the input range of 380 V to 420 V and output range of 28 V to 72 V DC voltage. Simulation results showed that the controller can quickly adjust the output voltage level for step variations in both line and the load. The controller can also set the output voltage level for both step and linear variations in the reference signal.