Design optimization of permanent magnet actuators
This study describes the design optimization of permanent actuators, of both rotary and linear topologies. Parameter scanning, constrained single and multi-criterion optimization techniques are developed, with due emphasis on the efficient determination of optimal designs. The modelling of devices by non-linear lumped reluctance networks is considered, with particular regard to the level of discretization required to produce accurate global quantities. The accuracy of the lumped reluctance technique is assessed by comparison with non-linear finite element analysis. Alternative methods of force/torque calculation are investigated, e.g. Lorentz equation, Virtual Work, and Maxwell Stress Integration techniques, in order to determine an appropriate technique for incorporation in a non-linear iterative optimization strategy. The application of constrained optimization in a design environment is demonstrated by design studies and experimental validation on selected prototype devices of both topologies.