Robust control strategy for a high-power off-board EV charger connected to grid-tied critical loads

One of the main duties of electric vehicles (EVs) is to provide smooth and robust power flow for the grid-tied loads in the vehicle-to-grid application. To this end, this paper proposes a comprehensive control system for a high-power off-board EV charger to appropriately generate/consume power when sudden reference power alteration and disturbance on the DC-link voltage measurement exist. The EV charger consists of two bidirectional DC/AC converter and single-phase dual active bridge (SP-DAB) converter which are connected to the power grid and EV battery, respectively. The grid-tied DC/AC converter is controlled using a two control-loop structure in d-q reference frame and also other controller including both steady-state and dynamic components are designated for the SP-DAB. In addition, the DC-link voltage robustness feature is evaluated based on analyzing the simultaneous effects of the SP-DAB transmitted power and phase shift angle (PSA) errors on the DC-link voltage error. MATLAB/SIMULINK environment is employed to illustrate the suitable responses of the high-power off-board EV charger.