Designing and Simulation of Current Controller for Active Magnetic Bearing

Active Magnetic Bearing (AMB) is a highly nonlinear and unstable system. This unstable attitude of Active Magnetic Bearing and its built-in nonlinearities make the designing and control problems really challenging. In this paper, a closed loop current controller for an active magnetic bearing (AMB) is designed to hover a ferromagnetic material at a particular air gap (10mm). There are two closed loops in an Active Magnetic Bearing; one is an inner loop for current control and other is the outer loop for position control. The inner loop comprises a current controller, power amplifier and an electromagnet coil. Electromagnet coil parameters are measured and calculated practically. Proportional-Integral (PI) controller is used as a current controller. Further, the inner closed loop of an Active Magnetic Bearing is imitated in the numerical computing environment and result exhibits the usefulness of the proposed controller design methodology.