SPV-BES System Feeding Power to Low Voltage AC Network and Nonlinear Loads

The high line impedance of the low voltage AC network (LVACN), coupled with the distorted currents drawn by the nonlinear loads at the point of common coupling (PCC), creates serious power quality issues in the AC network. Furthermore, higher penetration of renewable energy sources like the solar photovoltaic (SPV) in modern LVACN escalates such power quality issues because of their fluctuating behavior. In this context, this paper presents an adaptive filtering strategy-based control for the SPV-battery energy storage (BES) system feeding nonlinear loads to improve the power quality at the PCC. The adaptive filtering scheme ensures that the distortions in the load currents are not reflected in the LVACN. Thus, the currents and voltages in LVACN remain linear. Furthermore, a power management scheme is developed to optimize the operation of the SPV-BES system. It supports the PCC voltages by limiting the supplied and drawn power from the LVACN, during peak SPV array generation or low load condition and no SPV array generation or the peak load condition, respectively. The SPV-BES system is also capable of transferring its mode of operation from a grid connected system, to a standalone system, when the supply from the LVACN is interrupted. Thus, the overall system efficiency and reliability are enhanced. Both the simulation and the experimental analyses of the SPV-BES system are presented to demonstrate the effectiveness of the power management scheme and the adaptive filtering strategy.