Design and dynamic analysis of electromagnets for magnetic levitation application systems

This paper deals with design and dynamic analysis of rectangular-surface electromagnets for magnetic levitation application systems. On the basis of equivalent magnetic circuit (EMC) method and 3-D finite element analysis (FEA) model, initial and detailed design of an electromagnet are performed. By investigating static characteristics such as the variation of levitation force according to current under fixed air-gap length, the validity of the design is confirmed. And then, by employing a closed-loop PID control algorithm, the dynamic behavior of electromagnets is investigated experimentally. In particular, by adding temperature feed-back loop for the estimation of exact parameter in order to consider delay due to first-order lag element, the exact air-gap maintenance control can be acheieved.