Control strategy of a permanent magnet synchronous machine in the flywheel energy storage system

This paper is based on the flywheel energy storage system (FESS), and focuses on the vector control of the permanent magnet synchronous machine (PMSM). Considering the large inertia and very low speed acceleration of the FESS, a motor control strategy to avoid speed fluctuation is advanced during the process when the system starts from zero speed. When the flywheel battery is discharged, a motor control algorithm is proposed to maintain the DC voltage at a certain level. Meanwhile, a modified speed sensorless method based on model reference adaptive system (MRAS) is introduced to help increase the convergence speed at any time when the system switches into work. Simulation and experimental results show the validation of the proposed methods.