Robust output voltage controller for dynamic wireless charging of electric vehicles based on super-twisting algorithm

Dynamic wireless charging (DWC) systems for electric vehicles (EVs) represent an emerging technology that can accelerate the widespread adoption of EVs. Nonetheless, output voltage fluctuations are inevitable due to variations in the mutual inductance of the magnetic coupler. This article proposes an output fluctuation suppression method for DWC systems, and provides an effective output voltage regulation method against mutual inductance and load variations. Unlike existing control methods, the proposed cascaded super twisting sliding mode control (CST-SMC) for the secondary side buck converter of DWC can effectively compensate for mutual inductance variation. The proposed DWC system is designed consisting of two super twisting sliding mode control (ST-SMC) loops with a cascaded structure. In the inner loop, the ST-SMC is used to provide reference current tracking. In the outer loop, the second ST-SMC is employed to control the output voltage and generate the current reference. An experimental setup is built to verify the output regulation performance of the proposed control scheme. In addition, the proposed CST-SMC is compared with integral sliding mode control (ISMC) and cascaded PI control to validate the effectiveness of the proposed approach. Experimental results show a voltage fluctuation of approximately 2.77% is achieved at the output of the DWC system.