Model Validation and Input Voltage Closed Loop Regulation of a Bidirectional CLLC Converter

In this paper, the Extended Describing Function (EDF) method is used to predict the behavior of a bidirectional CLLC resonant DC-DC converter, deriving both the steady state model and the small signal model. These models are validated, comparing their results with the simulated results obtained in MATLAB environment. The input voltage to output voltage transfer function is derived from the small signal model and used to tune a PID controller. A closed loop control based on input voltage regulation is designed to ensure the desired output voltage. Its performances are evaluated under different work conditions in Simulink environment.