Accurate and Simple Modeling of Eddy Current Braking Torque: Analysis and Experimental Validation

A compact, reliable, and straightforward mathematical modeling of the eddy current (EC) braking torque is proposed in this article. First, the braking magnetic force, which curbs the movement of a rotating disk (RD), is evaluated using the basic laws of electromagnetism. Second, the braking torque is related to the braking force through a polynomial function model. The model parameters are evaluated by plugging in measurement samples in the equation of motion taking into account the nonlinear behavior of the aerodynamic drag forces. The proposed model neither has limitations on the braking system geometry nor the disk rotational speed as long as the measurement samples cover the whole speed range. Moreover, it is validated experimentally for constant and alternating magnetic flux profiles with best fit rates (BFRs) more than 85% and 93% for both rotational speed and braking torque, respectively. Furthermore, programmable braking application is demonstrated using the proposed approach and its applicability is verified experimentally.