An Adaptive Multi-Functional Control Strategy for Power Management and Voltage-Frequency Regulation of PV, BESS, and Hybrid Units in a Microgrid
Saeed Mahdavian Rostami, Mohsen Hamzeh
Abstract
This paper proposes an active-reactive power management technique in a microgrid consisting of Photovoltaic (PV) units, battery energy storage system (BESS) units, and hybrid (PV with BESS) units. The proposed strategy is a distributed technique that is equipped with a decentralized controller. In this approach, the decentralized controller calculates local frequency and voltage references according to the proposed adaptive droop characteristic, with the aid of information communicated via communication links. Although the proposed decentralized control strategy guarantees SoC balancing and precise active power sharing among BESS and hybrid units according to their capacities and the State of Charge (SoC) of BESSs, it cannot deal with other challenges in a microgrid. Therefore, a distributed control method is proposed to restore the frequency and voltage at nominal value, share accurately reactive power among all units (PV, BESS, and hybrid) according to their capacity, and curtail the PVs’ active power in a fairway during surplus active power generation. The proposed strategy completely deals with the variation of weather conditions (variation of the maximum active power and the reactive power capacity of inverters), load consumption, and changes in the power system. Simulation results in Matlab-Simulink are exhibited to verify the successfulness of the proposed control technique in various states of a microgrid while PV, BESS, and hybrid (PV/BESS) units constitute the power units of the microgrid.