Selection of the parameters of a permanent magnet synchronous machine by using nonlinear optimisation

The selection of the parameters of a permanent magnet synchronous machine (PMSM) is analysed using nonlinear optimisation. The constraints of the optimisation can be set to take the control principle into account. Compared with previously presented analyses, constant flux-based control as well as an absolute maximum criterion where no constraints are made to the control principle is analysed. Moreover, the requirements of the application are easily incorporated into the presented optimisation as additional constraints. On the basis of the results, the parameters of the PMSM (permanent magnet’s flux linkage and the direct and quadrature axis inductances) can be selected. The results show that when using a constant flux linkage-based control principle (e.g. direct-torque control) more torque can be obtained compared with minimum current vector control. After analysing the effect of different parameters, a design procedure is suggested and an interactive design programme is implemented with Matlab.