Performance of AMB Suspended Energy Storage Flywheel Controllers in the Presence of Time Delay

A flywheel suspended on active magnetic bearings (AMBs) constitutes a complex system including a rotor, flywheel disks, active magnetic bearings, auxiliary bearings, a motor/generator, control systems and energy conversion systems. The complexity of AMB suspended flywheel systems often makes the construction of their test rigs too costly in a research laboratory. We recently developed an experimental platform for AMB suspended energy storage flywheel. This platform serves as a test rig to assist the analysis and control design and was developed on the basis of a flexible rotor-AMB test rig previously constructed in the Rotating Machinery and Controls (ROMAC) Laboratory, University of Virginia. Two different control designs have been implemented on this platform: the mu-synthesis control and the characteristic model based all coefficient adaptive control (ACAC). In this paper, we examine the performance of the test rig in the presence of time delays. In particular, we show by simulation that this control design possesses considerable ability to resist the effect of time delays in the control inputs and/or output measurements.