Design of 2-DOF PID Compensator for Magnetic Levitation System

In recent years there are many advancements in the field of electromagnetics one among them is the development of Magnetic Levitation (Maglev) system. It has found various uses in fields such as high speed magnetic levitation trains, frictionless bearings, wind tunnel model levitation, vibration isolation of sensitive machinery, molten metal levitation in induction furnaces., lifts, conveyors etc. When this technology is applied to practical systems it will be affected by external disturbance and set point changes at the same time. So a multi-lens driver is required. Furthermore, the open-circuit maglev system is a highly non-linear and unstable system. Developing a proper control for such a system is really a demanding task.In this paper a 2-DOF PID compensator for the Maglev system is designed. Simulation is done using MATLAB and the results are compared with 1-DOF method. The additional feed forward components present improves the disturbance rejection capability and makes the system more stable when compared to 1-DOF controller. It is proved that 2-DOF controller provides both tracking and regulatory performance in an optimal manner. .