Investigation of Braking Torque Characteristic for a Double-Stator Single-Rotor Axial-Flux Permanent-Magnet Eddy-Current Brake

The braking torque characteristic of a double-stator single-rotor axial-flux permanent-magnet (PM) eddy-current brake (AF-PM-ECB) is studied. The parameters of PM width-to pole pitch ratio, copper thickness and speed are investigated to demonstrate how they can influence the braking torque. AF-PM-ECB is analytically and numerically explored in detail to reveal the fundamentals. The double-stator single-rotor AF-PM-ECB is analytically analyzed by 2-dimensional (2D) reluctance network modelling approach and 2D segmented layers are used to consider the actual 3D flux paths. The analytical approach is also improved by Russell-Norsworthys' factor to take the 3D effects into account. 3D finite element analyses (3D-FEA) are carried out to demonstrate the braking torque characteristic and validate the 2D segmented reluctance network modelling approach. A good match between the analytical and the numerical results are observed. It is shown that the copper thickness and PM width-to -pole pitch ratio have a significant influence on the braking torque characteristic of the AF-PM-ECB.