Adaptive Droop Controller for PV - Battery Based Microgrids

This paper deals with a decentralized power management for a microgrid fed by PV-battery hybrid distributed generation (DG) units. In this paper, a modified droop controller has been proposed to avoid the operation of batteries beyond their power limits. During peak power output from a particular battery, the proposed technique automatically reduces the perceived power rating of the hybrid DG and allows it to operate in grid-forming mode instead of switching to constant power mode. This has been achieved by dynamically shifting the P - omega droop lines vertically instead of changing the droop slopes. The effectiveness of the proposed control strategy has been validated through simulation studies on a two DG microgrid. The proposed control strategy can also be adapted to support frequency during severe power imbalance since battery power is conserved.