The invention discloses an integrated optimization method of a
flywheel energy storage system. The corresponding
system is formed by connecting a plurality of
flywheel monomers in parallel through a
direct current bus. The method comprises the steps that the real-time rotating speed, the direct-current
bus voltage, the maximum charging and discharging
power capacity and a
power grid frequency modulation power instruction of each
flywheel single body are collected; calculating current stored
kinetic energy based on the rotating speed and the rotational
inertia of the rotor, and normalizing to obtain an energy state index SoE; a double-layer collaborative architecture is adopted for power scheduling; at the moment of charging and discharging
mode switching, the total disturbance of the
system is estimated on line through a
cascade expansion
state observer, and feed-forward compensation is implemented in control output to suppress instantaneous fluctuation of the
voltage of the direct-current
bus. According to the method, the SoE is obtained by calculating the
kinetic energy and normalizing the
kinetic energy, so that the accurate representation of the
energy storage state is realized; and
voltage fluctuation can be effectively suppressed when working conditions suddenly change. The method avoids
overcharge and overdischarge of individual units, guarantees high reliability and safety, prolongs the service life of equipment, and is especially suitable for
power grid frequency support application in a high-proportion
renewable energy access scene.