Real-time investigation of grid-interactive EV charger with two-stage bidirectional converter under wide voltage range scenarios

With the increasing popularity of electric vehicles, the grid-interactive electric vehicle chargers (GIEVC) are very vital in utilizing them for ancillary services to support grid through V2G mode of operation. Further, the front-end converter of charger may have to face several Power Quality (PQ) issues such as voltage sag, voltage swell, and grid distortions, which are very common in weak grid. Therefore, the proposed work is mainly focused on developing control algorithm for GIEVC in order to handle the PQ issues while providing seamless transition from G2V to V2G mode of operations. Since the proposed the charger is of Level 1 for domestic applications; the typical nonlinear domestic load is also compensated in order to avoid the exaggeration of weak grid issues. Here, the major challenge is in extracting the fundamental voltage component from non-ideal grid voltage for which a cascaded non-identical second-order generalized integrator has been utilized. The efficacy of these algorithms is studied in MATLAB/Simulink simulations and validated using the real-time hardware platform using OP4510 RTLAB provided by OPAL-rt.