Abstract: The SB-7700 balancing monitor was used to carry out the online balancing experiment on the rotor-bearing unit of the flywheel energy storage system. The additional balance process flywheel was designed according to the balancing test results. The flywheel rotor-bearing system arrived at the rated speed of 3600 r/min after the rotor-bearing unit was balanced by the two-plane balancing method. The vibration monitor measurement showed that the vibration expressed some difference between the charging and discharging state. The discharging power rate had great impact on the amplitude-frequency performance at the resonance of the rotor-bearing unit. This was caused by the bias electrical-magnetic force of the permanent motor.

Key words: flywheel energy storage, rotor-bearing system, balancing