Predictive Frequency Regulation Control Strategy Based on Photovoltaic and Energy Storage in Islanded Microgrids

ABSTRACT Aiming at the problems of frequency fluctuation caused by load changes and low utilisation rate of renewable energy during the operation of isolated microgrids, a flexible power allocation strategy based on model predictive control (MPC) in which photovoltaic (PV) and energy storage (ES) jointly participate in frequency regulation is proposed. Taking the minimum frequency deviation and the highest energy utilisation as indexes, the optimisation objective function in the rolling time domain was constructed, and the weights of photovoltaic and energy storage output terms in the objective function were adjusted in real‐time to optimise their respective outputs. A fuzzy adaptive controller (FAPPT) is designed, which makes the photovoltaic array run in the fuzzy adaptive power tracking mode with power reserve adjustable up and down flexibly; and realises bidirectional regulation of microgrid frequency by adaptive increase or decrease of power reserve. Compared with the simulation of traditional MPPT and FAPPT control, it is verified that the proposed strategy makes the system frequency more stable, improves the energy utilisation rate, and has the characteristics of low dependence on model parameters.