Multifunctional Control for PV-Integrated Battery Energy Storage System With Improved Power Quality

Abstract

In this work, a multifunctional control is implemented for a solar photovoltaic (PV) integrated battery energy storage (BES) system (PVBES), which operates both in the grid-connected mode (GCM) and a standalone mode (SAM). This system addresses the major issues of integrating power quality enhancement along with the solar PV generation. Thus, a multifunctional control of voltage source converter (VSC) is implemented to provide the load compensation, harmonics mitigation, unity power factor, and an automated transition between GCM and SAM in PVBES. A single VSC is used to control the active power and to maintain the power quality in this PVBES. Furthermore, due to an automated transition in the system, the local loads have continuous power irrespective of the grid accessibility. The main challenges addressed are the operation of an automated transition between GCM and SAM with the least disturbance to the nonlinear loads. The integration of a BES enables the SAM operation and improves the reliability of the PVBES. The charging and discharging of BES are controlled by using a dc–dc bidirectional converter. The performance of the implemented controls is tested using a real-time processor (dSPACE-1202) and validated through test results for steady state and dynamic conditions. In all operating conditions, the harmonics content of the grid current is maintained less than 5%, which follows the IEEE standard 519-2014.