magnetic bearings, active control, flywheel, railway, energy storage
A system configuration to be applied to the railway system using flywheel energy storage system to store regenerative energy which is produced during the braking period of the train is presented. The proposed FESS (Flywheel Energy Storage System) is small scale model and has 100W output power, 20,000rpm rotational speed. In general railway trains generate regenerative energy for 10-20 sec when the train brakes and also high traction energy is needed for very short moment (10 sec) when the train increases the traction force. Considering such characteristics of the railway system energy storage system for the railway should have very fast response property. Among the various energy storage systems flywheel energy storage system has the fastest response property, which means that flywheel ESS is the most suitable for the railway system. The effectiveness of the proposed flywheel energy storage system is shown based on the 20,000rpm high speed rotational test and also the applicability of the proposed configurations to the railway system is presented by using the energy conversion of the flywheel energy storage system that indicates the charging of the regenerative energy and discharging for the traction force based on the load test.