Green Energy Based Multipurpose EVs Charging Station with Flexible DC Charging Functionality for Residential/Commercial Building Applications

An implementation of a multipurpose charging station (MCS) having the capability to operate in both grid-connected mode (GCM) and standalone mode (SAM), electrified by solar photovoltaic (PV) array and supported with battery energy storage (BES) system and 1-Φ grid is realized in this work. The presented MCS exhibits multipurpose functionality, as it not only provides uninterrupted charging to electric vehicles (EVs) but also satisfies the demands of critical household loads while providing required active/reactive power support to the utility grid. Notably, the presented MCS ensures both AC charging and DC charging facilities to the EVs owners. Further, its DC charging ports cover a flexible voltage range of 50V to 500V, and therefore, satisfactorily cater the demands of all types of low voltage (LV) and high voltage (HV) EVs parked in the building parking spaces. In order to realize such flexible DC charging functionality, a buck-boost bidirectional DC-DC converter (BDDC) with integrated magnetics is employed at the DC charging ports of the MCS. Besides, the presented MCS ensures required active/reactive power support to the grid during GCM operation, and also, eliminates the negative impact of PV and load intermittencies on the grid. Finally, the high-performance fourth-order quadrature signal generator (QSG) named cascaded non-identical second-order generalized integrator (CNISOGI-QSG) based PLL is used under steady-state and synchronization conditions to realize a high performance control of the MCS under both normal and abnormal operating conditions. At last, the MATLAB simulation results are used to verify the performance of MCS under various operating conditions.