Sliding mode control of dual active bridge converter based on hyperbolic tangent function

A sliding mode control (SMC) based on hyperbolic tangent function (HTF) is proposed for dual active bridge (DAB) converters to improve the voltage stabilization performance of output voltage. SMC has gained widespread utilization due to its robustness and its ability to enhance the dynamic performance of nonlinear systems. Nevertheless, the traditional SMC has the problem of buffeting and tracking performance degradation. The SMC based on HTF combines the advantages of SMC and suppresses the buffeting problem. Therefore, the stability and robustness of the output voltage are improved, and accurate reference voltage tracking is realized. To accomplish this objective, a mathematical model of the DAB converter is initially formulated, grounded in the dynamic equation of the output voltage and the power transfer equation, which is taken as the model equivalent part in SMC. At the same time, HTF is used as the switching part and the equivalent part of the model to compare the displacement, and the stability of the control method is established through rigorous analysis using the Lyapunov stability criterion. In the end, in the Matlab-Simulink environment, the proposed SMC based on HTF is simulated and verified.