Full-Bridge LLC Resonant Converter with Super-Twisting Non-Singular Fast Terminal Sliding Mode Control

In response to the problem of large dynamic overshoot in the traditional proportional-integral (PI) control of full-bridge LLC resonant converters, a novel control strategy based on the super-twisting non-singular fast terminal sliding mode (STNFTSM) is proposed. Firstly, this paper describes the basic principles of LLC resonant converters. Then, an improved super-twisting algorithm is proposed, and the STNFTSM controller is designed based on it. The design process of the sliding mode controller is described in detail Finally, the proposed online optimization strategy is validated in the Simulink simulation platform. The experimental results demonstrate that the proposed STNFTSM control method can significantly reduce the dynamic response overshoot of the system and eliminate the steady-state chattering problem of traditional sliding mode controllers.