Robust Controller Design for Phase-Shifted Full-Bridge Series Resonant Converter under the Nonlinear Load

Abstract

In this paper, a third-order sliding mode control (3-SMC) scheme is proposed for the phase-shifted full-bridge series resonant converter (PSFB-SRC) which has a nonlinear characteristic and experiences the nonlinear load variation when it is used in DC/DC power supply application. 3-SMC is effective in compensating the nonlinear load variation in nonlinear system. The system modeling of resonant tank and output filter are derived, and the 3-SMC which is comprised of an equivalent controller and a switching controller is developed. Numerical simulations are performed to validate the proposed control approach.