Capacity configuration method of flywheel energy storage system considering power characteristics of generation-energy storage-load

In the application scenario of DC fast charging station of electric vehicles, a capacity configuration method of flywheel energy storage system considering power characteristics of generation-energy storage-load is proposed to limit the ramp rate of grid power and compensate the bus voltage drop. Firstly, according to the power relationship of generation-energy storage-load, the ratio of the increment of flywheel’s mechanical angular velocity to the bus voltage sag amplitude is approximately a function of time. According to the power characteristics of grid-side converter in the fast charging station, it is deduced that the relationship between the maximum grid power ramp rate and the maximum sag amplitude of bus voltage is approximately proportional. Then, for the fast charging load with different rated power, the setting of the rotational inertia of flywheel rotor and the initial mechanical angular velocity is emphatically discussed, and the capacity cons-traints of the energy storage converter of the flywheel side are analyzed, on the basis of satisfying the DC bus voltage level and the electromagnetic constraint of permanent magnet synchronous motor. Finally, the system simulation model is built in MATLAB/Simulink to verify the correctness of the capacity configuration method of flywheel energy storage system. © 2020, Electric Power Automation Equipment Press. All right reserved.