Analysis and design optimisation of a double pm-rotor radial-flux eddy current coupler, A.S. Erasmus and M.J. Kamper, IEEE energy Conversion Congres and Expo,

In this study a semi-analytical calculation method for obtaining 3D solutions for the torque of radial flux permanent magnet eddy current couplers is presented. In this way the use of computationally expensive transient 3D finite element solutions is avoided, which is very important when it comes to the design optimisation of these machines. The proposed analytical method takes the effect of flux density harmonics into account. The 3D end-effects are taken into account by using Russell's coefficient. The accuracy of the proposed semi-analytical calculation method is evaluated against extreme variation of machine dimensions. It is shown that this fast calculation method can be used with great accuracy in the design optimisation of these couplers.

Computationally efficient analysis of double PM-rotor radial-flux eddy current couplers, A.S. Erasmus and M.J. Kamper, IEEE Transactions on Industry Applications,

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.

Multi-objective design optimisation and pareto front visualisation of radial-flux eddy current coupling for a wind generator drivetrain, A.S. Erasmus and M.J. Kamper, 2016 IEEE Energy Conversion Congress and Exposition (ECCE),

In this paper the design optimisation of a 2.2 kW, double rotor, radial axis eddy current coupling operating at 97 % efficiency, designed for a wind turbine drive train application is described. A computationally efficient finite element analysis in conjunction with gradient (MMFD) and population (NSGA) based design optimisation algorithms is used in order to obtain an optimal coupling design. The two optimisation algorithms are evaluated in terms of speed and accuracy. The comparison between copper and aluminium conductor materials revealed that the aluminium is the preferred material in terms of mass and cost. A gradient-based analysis method with regard to the input parameters of the genetic optimisation algorithm's pareto curve is proposed.