Design and implementation of flywheel energy storage system control with the ability to withstand measurement error

In this paper, attempts are made to design an offset and dead zone resistant digitalized vector control system for the flywheel energy storage system (FESS) based on the permanent magnet assisted synchronous reluctance motor (PMa-SynRM). Typically, in the motor drive set, current sensors are used. Current sensors in the industrial application consist of offset and dead zone phenomena and disturb the performance of the control system. Therefore, the effects of these phenomena in FESS designed control system are investigated, and a modified control system with using a proper filter to eliminate these phenomena is proposed. The proposed filter can eliminate these phenomena from the measured current without any decreasing in signal magnitude. The proposed control system eliminates speed ripple caused by the dead zone and offset effects. The performance of FESS is improved under the modified control system. Simulation and experimental results of the modified control system for FESS are presented to verify the performance of the energy storage drive and the theories.