CAPSA based Control of Solar PV Array Integrated EV Charging Station Operating in Standalone, and Grid Connected Modes

In this paper, a solar PV (Photo Voltaic) array, and a storage battery integrated three phase charging station, is proposed that provides both AC and DC charging to electric vehicles (EVs). In daytime, the charging station operates in standalone mode to charge the EV connected at point of common interconnection (PCI). However, the EV with the DC charger, takes power from the storage battery. Whereas, in absence of solar PV generation, the charging station takes power from the grid. In grid connected mode, the control of voltage source converter (VSC) is realized using convex combined affine projection sign algorithm (CAPSA). This algorithm convexly combines the output of two APSA with large step size and small step size. Therefore, the proposed algorithm achieves fast convergence, and low steady state error in abruptly changing input conditions. Therefore, the proposed algorithm is suitable for EV charging station where the charging current of the EV changes frequently. Moreover, while connecting the charging station to the grid, the charging station synchronizes the PCI voltage to the grid voltage to achieve the seamless mode transition. In grid connected mode, it also improves the quality of the grid current in terms of total harmonic distortion (THD), and makes the grid currents sinusoidal. Various steady state and dynamic condition results are taken on the experimental prototype developed in the laboratory to demonstrate its satisfactory behavior.