Control of Solar PV-Battery System to Limit in PCC Voltage Rise and for Power Quality Improvement

The point of common coupling (PCC) voltage of the grid integrated solar photovoltaic (GSPV) system rises when the load becomes less and the SPV array generation at its peak, leads to the overvoltage at the PCC. It causes the system to shut down its operation to protect itself and the load from the overvoltage. The GSPV system also suffers from substandard power quality (PQ) due to the unbalanced or nonlinear load currents. This work addresses these issues and presents the control scheme for the GSPV-battery system. This work presents the variable power mode of operation to restrain the rise in PCC voltages below its maximum permissible limit as set by the IEEE std. 1547. The system operates either in unity power factor (UPF) mode or the constant power generation (CPG) mode or in voltage regulation (VR) mode, depending upon the battery status and PCC voltage amplitude. The system also provides shunt compensation at PCC to reduce the negative impact of the unbalanced-nonlinear load currents in the AC grid and maintains the PQ in the AC grid as per the IEEE std. 519. A simulation study is performed to demonstrate the efficacy of the presented control algorithm.