A review on active & reactive power control strategy for a standalone hybrid renewable energy system based on droop control

Renewable energy sources (RESs) combined with energy storage can significantly increase the resilience of standalone systems. However, the intermittent nature of renewable energy resources creates a number of operational challenges for standalone systems. In this paper, the potential challenges facing the operation of a standalone hybrid system with solar photovoltaic (PV) and wind turbine energy generation and battery energy storage are addressed. Control strategies for the system sources are developed to mitigate the potential challenges. A droop-based voltage and frequency control strategy is proposed for the battery energy storage to balance the mismatch between the renewable generation and the load and to maintain the system stability. An active and reactive power control strategy with maximum power point tracking (MPPT) is proposed for the PV and wind sources to maximize the generation when there is a lack of energy resources and to supply quality power from the sources. The proposed control strategies are able to regulate the system voltage and frequency within the acceptable ranges irrespective of variations in the sources and the load-demand.