Nonlinear Control of a Three Phase AC/DC Converter for EV Chargers

Abstract

this paper presents the modeling and control of a three-phase bidirectional AC/DC converter used as the grid-side stage of an electric vehicle (EV) on-board charger. The converter interfaces the electrical grid with the battery pack through a DC-link and is required to ensure unity power factor operation, accurate DC-bus voltage regulation, controlled active and reactive power exchange, and reliable bidirectional power flow for safe charging and discharging processes. To achieve these objectives, three control strategies are investigated and compared: conventional field-oriented control (FOC), nonlinear backstepping control (BSC), and integral backstepping control (IBSC). All controllers are implemented within a cascaded dqframe control architecture with decoupled current dynamics. Their performance is evaluated through MATLAB/Simulink simulations, focusing on dynamic response, robustness, and power quality under grid-connected operating conditions. The results demonstrate the superior performance of the IBSC strategy in terms of tracking accuracy, robustness against disturbances, and overall control effectiveness compared to FOC and conventional BSC.