Adaptive Current Control for a Bi-directional Interleaved EV Charger with Disturbance Rejection

This paper presents a multi-leg variable frequency converter based electric vehicle (EV) charger with improved adaptive current modulation strategy for fast charging operation from a single-phase distribution grid. The multi-leg bridgeless converter provides a higher utilization of input energy with a reduction in electromagnetic interference (EMI). The proposed configuration is more robust towards frequent parameter variation as the high-frequency converter leg reduces the requirement of large passive components. An adaptive sliding mode control (ASMC) has been introduced for faster dynamical control during grid-to-vehicle (G2V) and vehicle-to-grid (V2G) with diverged distribution grid conditions. The ASMC provides a better dynamical response as the tracking error is confined within the pre-defined sliding surface during an abrupt change in adaptive gain variation. The proposed control action virtually eliminates the proportional-integral (PI) controller to address more nonlinearities during the EV charging operation. A MATLAB & SIMULINK model is developed to study the various dynamical response of the converter and proposed control action. A hardware laboratory prototype is also designed for a 3.3 kW EV charger to validate the desired character with the improvement of the source-end power factor during active power exchange in the G2V mode of operation.