Power Quality Improvement and Signal Conditioning of PV Array and Grid Interfaced Off-Board Charger for Electric Vehicles with V2G and G2V Capabilities

Abstract

In this work, we present a photovoltaic (PV)-based off-board charging system integrated with the grid using a voltage source converter (VSC). The control of the grid-tied off-board charger is derived from the joint logarithmic hyperbolic cosine robust sparse adaptive filter (JLHCAF) algorithm. This algorithm effectively tracks the fundamental component of the load current in a short duration, providing a good dynamic response. Due to its robustness against impulsive interference, the JLHCAF outperforms other sparsity-aware robust algorithms The cascaded proportional-integral (PI) controller is used to control the bidirectional buck-boost converter for electric vehicle (EV) charging/discharging, which acts in buck operation if the EV is being charged and in boost operation if it is discharged. The reference DC link voltage for the controller is derived by using adaptive MPPT technique. The bidirectional properties of the system enable various functions, including grid-to-vehicle (G2V), vehicle-to-grid (V2G), PV source-to-grid (PV2G), vehicle-to-home (V2H), and PV source-to-vehicle (PV2V) operations. Additionally, the system can supply power to critical nonlinear loads. The control strategy ensures compliance with the power quality requirements set by the IEEE standard, as demonstrated in the results. To validate the effectiveness of the proposed system, we conducted tests under dynamic conditions by disconnecting and reconnecting household loads. Furthermore, the off-board charging system was subjected to actual conditions, such as variations in solar PV insolation, and its steady-state performance was evaluated through simulation and laboratory experimental prototypes. The results, including total harmonic distortion (THD), support the validation of the developed charging system.