A sophisticated active magnetic bearing system with supreme reliability

Within this work a new active magnetic bearing (AMB)-system offering supreme reliability is presented. It provides bearing capacity even in case of a defect within any sub-assembly over the whole operating time. Each AMB consists of completely decoupled electro-magnet (EM)-channels configured in hot redundancy, comprising a singular EM, controlled and driven by a decentralized hot-swap controller amplifier module (HCA) and one displacement sensor. Each HCA is responsible for controlling the position of the structure towards its dedicated EM and comprises a digital controller, a switching amplifier, local power supplies, and a local error detection unit. All functional EM-channels contribute to support the structure. On occurrence of an error within a certain EM-channel this error is detected by the local error detection unit and the defective EM-channel auto-matically shuts down. The adjacent redundant EM-channels take over the bearing functionality and the defective sub-assembly can be replaced during system operation (hot-swap) without degrading system performance. This paper gives detailed information on the AMB functionality and the HCA design.