Classical Control Techniques Used in Controlling of An Active Magnetic Bearing System

Extreme high-speed rotation in a harsh environment with less or no maintenance is nowadays a ubiquitous requirement of heavy industries and automobiles. Among many options, Active Magnetic Bearing (AMB) is the best suited for the requirement. However, the inherent nonlinearities of AMB make researchers to introduce the knowledge of controllers for a stable bearing operation. In this paper, a proposed Active Magnetic Bearing system is first mathematically modelled and linearized in the form of a transfer function. Later for a particular value of the air gap, the transfer function of AMB is calculated and simulated with a Lead controller in a closed-loop form. To further improve the performance of this closed loop a Proportional-Integral-Derivative (PID) controller is used and simulate in a closed-loop form. For both of the controllers, time domain analysis and frequency response analysis is observed, and various parameters like peak overshoot, peak time, rise time, settling time phase margin, gain margin etc. are calculated. Finally, a comparison is carried out to conclude which one of the controller performances is better considering the data obtained from transient state analysis.