Multifunctional Bidirectional Charging System for EVs and Grid with Improved Power Quality Using a Sparse Proportionate-NLMF Based Method

Electric vehicles (EVs) are one of the more emerging and significant areas, representing the future of transportation. Moreover, the increased demand for EVs brings greater attention toward the development of the charging infrastructure. Therefore, this paper addresses the multifunctional charging system integrated with the grid, EV battery and household utilities. It presents an improved idea about the charging system with grid connection and its connection to the varying local nonlinear load. It consists of a voltage source converter (VSC) tied to the grid and bidirectional converter, which charges/discharges the battery and also regulates the constant voltage across the DC bus, where all the vehicles are connected for charging. It also shows the operations of charging/discharging the battery of EVs and the voltage and current profile across the battery as per the state of charge (SOC) limits. Moreover, the sparse constrained proportionate normalized least mean fourth (SCP-NLMF) based method is used to control the charging system by estimating the active component of load current. The derived mean square error (MSE) of load current is improved due to low convergence rates in later periods. The adaptation process becomes more accurate by mitigating the MSE error of load current to converge faster and the dynamic response is further improved. The simulated and tested results validate the accuracy and efficacy of the SCP-NLMF technique and charging system.