Control of single axis electromagnetic levitation system

One of the most attractive topics in engineering is Magnetic Levitation (Maglev). Maglev is an example of creating anti-gravity force. Maglev train is an application of this subject and single-axis electromagnetic suspension system (SAEMSS) is the first stage of them.In this study, SAEMSS is studied in terms of mathematical modelling and controlling. Mathematical models of the SAEMSS with the solenoid-type and U-type electromagnets are derived. This model contains second order polynomial because of magnetic force equation. Therefore, system is nonlinear and cannot be controlled by using linear control techniques. To overcome this problem the nonlinear equation is linearized at the equilibrium distance using Taylor series expansion method. PD and phase-lead compensators are designed to control the linearized unstable system.Hall-effect sensor is used in solenoid type electromagnetic levitation system (ELS) and inductive sensor used in U-type ELS. Microchips? dsPIC30F4011 is chosen to process the measurement data and to generate the control signals.A metal ball or a permanent magnet disk is successfully levitated at the certain set position with desired performance criteria against gravity force. Results of the simulation and experimental works show that phase lead controller has better performance than PD controller for both systems.