Cooperative control strategy for distributed wind-storage combined system based on consensus protocol

Abstract

To realize real-time wind farm output power regulation with power-sharing among storage devices that have different state of charges (SoCs), this paper proposes the cooperative control of the distributed wind-storage combined systems (WSCSs). It firstly establishes the mathematical model of doubly-fed induction generator (DFIG) and hybrid energy storage system (HESS) and implements the controls for two devices, respectively. Secondly, based on the power consensus protocol, an active power cooperative control strategy of the distributed WSCSs is proposed. It ensures that the energy storage devices can cooperatively compensate for wind power according to their different capacities to regulate the output power of the wind farm (WF) in real-time. At the same time, the high- and low- frequency power fluctuations can be effectively shared by the supercapacitors (SCs) and batteries, overcoming the deficiencies of the conventional battery energy storage system (BESS). Then, considering that the SoCs of the batteries are not identical, this paper further proposes a DFIG grid-side reference power adjustment strategy based on consensus protocol. It guarantees that each HESS can effectively achieve power-sharing while regulating the output power according to the SoCs of batteries. Finally, simulations in PSCAD/EMTDC under various scenarios are conducted to demonstrate the effectiveness of the proposed control strategy.