The super-twisting sliding mode control for half-bridge three-level LLC resonant converter

The zero-voltage switching capability of the half-bridge three-level LLC resonant converter(HBTHLLC) is possible, and the switch's maximum withstand voltage is just half the input voltage. High efficiency, minimal electromagnetic interferencehigh power density, and high power density are benefits of the converter. However, the HBTHLLC is a complex high-order system with dynamic characteristics drift problem, and its nonlinearity also brings great challenges to the design of the closed-loop controller. In this paper, a new super-twisting sliding mode(STSMC) control strategy is proposed for the HBTHLLC. This control strategy does not need to consider the internal parameters of the system, but only needs to solve the first derivative of the input, which is easy to calculate. The control strategy is simulated and verified in Simulink, and this method has good dynamic response ability and robustness.