Development of 5kWh Flywheel Energy Storage System Using MATLAB/xPC Target

A 5 kWh class FESS (flywheel energy storage system) with the operating speed range of 9,000~15,000 rpm has been developed. The system consists of a composite flywheel rotor, active magnetic bearings, a motor/generator and its controller. Because active magnetic bearings(AMB) to support the rotor vibration are open-loop unstable, they needs a feedback controller for stable operation. Digital controller and notch filters have been designed and implemented on a MATLAB/Simulink and xPC target with 10 kHz sample rate. MATLAB/xPC target which is PC based real-time controller is useful to get FRF (frequency response function) of AMB and implement the notch filters and the control algorithms. This paper introduces the FESS mounted on AMBs being controlled by xPC system and the experimental results up to 15,000 rpm.