Synchronization and De-Synchronization of Single Stage PV- Battery based Microgrid for Enhancing Power Grid Resilience

This paper deals with synchronization and de-synchronization of three phase four (3P4W) photovoltaic (PV)-battery energy storage (BES) based hybrid microgrid to enhance the resiliency of power grid. The PV-BES microgrid provides grid neutral current, reactive power and harmonics mitigation in the utility tied mode and undisturbed energy to emergency loads at the disappearance of the grid and PV array. In grid integrated mode, variable learning based adaptive current controller is utilized. The PV feed forward concept is incorporated for fast convergence under dynamic change by reducing burden on outer Proportional-Integral (PI) voltage loop. In islanding operation, load voltages, are kept sinusoidal by standalone control. The BES charging/discharging is maintained through the bidirectional converter with regulation of DC link voltage. The direct mode transition algorithm detects utility variables utilizing voltage and variations in phase and frequency for changing the operating modes with smooth transfer between these modes. The effectiveness and mode transfer capability of suggested controls are verified by experimental results.