Flywheel Energy Storage System with Synchronous Machine for High Proportion New Energy Connected Power Grid

In line with the global dual carbon goals, high proportion of renewable energy and high proportion of power electronic equipment will become the development trend of the future power grid, and the accompanying system operation safety issues will become increasingly prominent. Energy storage has good controllability and fast regulation characteristics, which can suppress fluctuations in new energy generation. However, at the same time, it further increases the proportion of access to power electronic equipment, exacerbating issues such as low inertia and underdamping. Although virtual synchronous machine technology can be used to address this issue, it sacrifices energy storage capacity and increases control complexity. In this paper, a novel flywheel energy storage system (FESS) with synchronous machine (SM) is proposed, where the SM is directly connected to the grid, then its real inertia and damping can be used for power grid support and only a partial capacity inverter is needed. The topology and operation principle of the FESS are analyzed in detail, and a simulation has been carried out to validate the effectiveness of the proposed FESS.