Optimization of permanent magnet motors using field calculations of increasing precision

An algorithm is given for the fast optimization over a constrained domain of an objective function calculated iteratively. To apply the algorithm to optimizing the efficiency of permanent magnet synchronous motors, an iterative magnetic field calculation is employed, featuring a novel procedure for achieving convergence of nonlinear reluctivity. For each set of motor parameters constituting a point in the optimization search, the iteration of the field calculation is continued until the change in the objective function is below a preset sequence of tolerances