A Reliable Magnetic Bearing System for Turbomachinery

A reliable magnetic bearing system for turbomachinery was fabricated and tested. The bearing system features high performance, high temperature actuators with integrated sensors, and an advanced rotor control system. Fault tolerance was achieved by using redundant sensors and actuator coils. The control system, which uses a triple modular redundant architecture with four processors, was integrated with the sensor electronics, amplifiers, and power supplies. The control software takes advantage of the redundant sensors and coils to provide continuous operation even in the event of a sensor, coil, or amplifier failure. The control system also includes an automatic inertial balancing system, which minimizes forces transmitted to the stationary structure by shaft unbalance. An advanced monitoring system was developed, which interfaces to the control system. It monitors system performance such as rotation rate, rotor position, and unbalance. The monitoring system also analyzes the unbalance, calculating its location and magnitude. The bearing was tested at temperatures up to 800 degF (427 degC).