The CLLC full-bridge resonant converter suffers from slow response speed, poor dynamic performance and poor interference immunity when compensated by traditional control strategies, and this paper proposes a composite control strategy based on improved sliding mode self-immunity. Firstly, a nonlinear model of the CLLC full-bridge resonant converter is established by the extended function description method, and the system is fitted using the frequency sweep method. Secondly, the self-immunity linear extended observer is designed to estimate and compensate the error, the super-helix sliding mode algorithm is used to replace the traditional error feedback control law in self-immunity, the self-immunity error feedback control rate is optimised, and the sliding mode surface and super-helix sliding mode structure are improved, and once again, the jitter vibration phenomenon of the system is effectively reduced by using the smoothed sigmoid function instead of the discontinuous sign function. After that, the parameters of the controller are optimised by PSO algorithm to improve the stability of the system. Finally, the effectiveness of the improved super-helical sliding mode self-immunity control strategy is verified by simulation and experimental analysis. The results show that the strategy effectively improves the problems of output voltage overshooting and long regulation time of the traditional PI controller in the case of sudden change, and has good dynamic performance and robustness.

Siwen Qi. Research on Sliding Mode Active Disturbance Rejection Control Strategy of CLLC Resonant Converter. International Journal of Frontiers in Engineering Technology (2025), Vol. 7, Issue 3: 101-110. https://doi.org/10.25236/IJFET.2025.070314.

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