Control strategy and optimal configuration of energy storage system for smoothing short-term fluctuation of PV power

Abstract

With the increase of the penetration rate of photovoltaic (PV) power plant in the power system, PV power fluctuation has become one of the important factors affecting the power quality. The energy storage system (ESS) is an effective way to smooth short-term PV power fluctuation and has been widely used. The control strategy is a key factor that will influence the smoothing effect and size of ESS. In this paper, by using ESS to smooth PV power fluctuation, we proposed a novel control strategy that can regulate the state of charge (SoC) of the battery and calculate the output power of ESS based on the super short-term prediction of PV power. Besides, the rolling prediction theory is introduced into the control strategy, which makes the regulating process be implemented at every sampling moment. Based on this control strategy, an optimal sizing model of ESS is built to analyze the economy of the combined system. Finally, actual data of a PV power plant are used for simulation and verification. The results demonstrate that the proposed strategy can smooth the PV power fluctuation effectively. The total cost and the power of exceeding limitation both are reduced.