Computationally Efficient Analysis of Double PM-Rotor Radial-Flux Eddy Current Couplers

In this study, a semianalytical calculation method for obtaining 3-D solutions for the torque of radial-flux permanent magnet eddy current couplers is presented. In this way, the use of computationally expensive transient 3-D finite element solutions is avoided, which is very important when it comes to the design optimization of these machines. The proposed analytical method takes the effect of flux density harmonics into account. The 3-D end-effects are taken into account by using Russell's coefficient. The accuracy of the proposed semianalytical calculation method is evaluated against extreme variation of machine dimensions. The Russell end-effect factor is evaluated and found to be inaccurate for axially short and radially large couplers. A prototype coupler with different conductors was tested to validate the proposed semianalytical torque calculation method.