Nonlinear high-gain observer for a three-pole active magnetic bearing system

This study is to design an observer for the rotor position of a voltage-controlled 3-pole active magnetic bearing (AMB) system. The observer will be based on the input voltages and coil currents that drive the magnetic poles. Such an observer can be utilized in the sensorless control of the AMB system. Due to the strong nonlinearity in the dynamics of 3-pole AMB system, the theory of nonlinear high-gain observer is adopted to design the observer. The obtained observer is verified numerically and experimentally.