Small-signal model and feedback controller design of constant-voltage and constant-current output control for a phase-shifted full-bridge converter

In this study, the feedback controllers were designed and implemented to fulfill the constant-voltage (CV) and constant-current (CC) output modes for a power converter. This converter's power stage was composed of a stand-by power, power factor corrector, and DC-DC converter. The topology used by the DC-DC converter was a phase-shifted full-bridge with a parallel current-doubler rectification converter (PSFB-PCDRC). To design the feedback controllers for the PSFB-PCDRC CV and CC operations, the PSFB-PCDRC small-signal model was established and employed to analyze frequency responses. Moreover, the three-terminal switch model and state-space representation were used, therefore, the PSFB-PCDRC transfer function was available to be acquired for the Bode plot simulation and analyzing. According to practical measurements, the derivation of small-signal model and loop compensative parameters could be approved. Simulations and experimental results corresponded to the anticipated results of theory, demonstrating the validity of proposed design.