Modeling and Robust Control with Virtual Inertia for Super-large-Scale Battery Energy Storage System

A secondary coordinated control method with virtual inertia is proposed in this paper, which takes full advantage of the large capacity of energy storage in the super-large-scale energy storage system. Firstly, the architecture of super-large-scale energy storage system and the structure of control system based on power converter are constructed. Accordingly, the non-linear model of the system is established and the virtual synchronous generator model is equivalent. Meanwhile, the influence of different virtual inertia on the output frequency of the system is investigated. Based on these, a secondary coordinated controller is designed by using robust control method. As a result, it can solve the asynchronous problem of voltage and frequency when multiple energy storage units are connected to the grid in large-scale energy storage system, due to the complexity of equipment and the limitation of conventional control system architecture. Finally, a simulation system of energy storage station is built to verify the control effect of virtual inertia and the designed secondary coordination controller.