Optimal Control of Hybrid Photovoltaic/Battery Energy Storage System for Mitigating Voltage Sag

This paper presents development of an optimal control strategy for a hybrid photovoltaic/battery energy storage (PV/BES) system. The fluctuations at the DC bus voltage due to voltage sag were mitigated by using charge/discharge capability of the BES through the DC/DC buck/boost converter. Furthermore, an optimization of system control parameters responsible for DC bus voltage regulation within the grid side voltage-sourced converter and DC/DC buck/boost converter were introduced by using simplex optimization method. The control system performances were evaluated for different simulation case studies such as the cases with and without BES as well as the system with optimized control parameters