Energy Shaping Based Sliding Mode Control for Dual-Mode Phase-Shifted Full-Bridge Converter

Dual-mode phase-shifting full-bridge (PSFB) converter is popular for wide-input-voltage applications. To tackle the control difficulties arising from wide input-voltage and load variations, an integrated extended state observer (ESO) along with sliding mode control based on an energy sliding surface is proposed. By employing passive control schemes to accelerate the convergence of inductor energy and introducing energy feedforward via equivalent resistance, the stability, fast dynamic response, and robustness of the overall system are ensured. Simulation results verify that the proposed approach outperforms conventional PI dual-loop control in terms of load transient response, input/output voltage variation rejection, reduced overshoot, shorter settling time, and smooth mode transition. This strategy offers an effective solution for isolated DC-DC converters requiring multi-mode input operation and high dynamic performance.