The paper assesses the determination of the inductances of five-phase permanent magnet machines with magnets not directly facing the airgap but surrounded by a laminated steel rim to secure the magnets (interior permanent magnet synchronous machines, IPMSM). This particular design increases the mechanical robustness of the rotor but precludes the use of known analytical expressions to estimate the inductances. Therefore, we estimate self and mutual inductances through static analysis with the Finite Element Method under different working conditions, thus obtaining three sets of parameters. As an approximation, we assumed that the inductances can be considered independent of the rotor position. However, they can change under the influence of the stator currents and saturation of the stator and rotor iron parts. To assess the accuracy and correctness of each set of inductances, we used them in an analytical model of an existing prototype; subsequently, we compared the stator currents and the electromagnetic torque under steady state with corresponding results obtained through the Finite Element Method using the package ANSYS-Maxwell®. From this comparison, we concluded that the most appropriate inductances are those obtained without magnets in the rotor.

This work presents a new method to estimate the electrical parameters of five-phase permanent magnet synchronous machines, including those related to the third-harmonic of the air gap induction, based on the instantaneous impedance of the stator. Besides rotor speed, the proposed procedure requires the measurement of stator phase voltages and currents during a transient no-load startup. The estimates of the parameters are the solution of an optimization problem that compares experimental instantaneous impedances of d-q models with their analytical counterparts. Simulation results indicate the potential of the proposed method to provide accurate estimates of the electrical parameters and flux linkages produced by the permanent magnets. Finally, an accurate knowledge of electrical parameters is essential to several high-performance applications.

This work presents a method to estimate the electrical parameters of the double-cage model of induction motors using only data available in manufacturer data sheets. The parameters are obtained by solving a numerical optimization problem based on the steady-state equations of the induction motor and the manufacturer data through the Genetic Algorithm. To test and validate the method, we present experimental results of 100 motors with power ranging from 35 to 75 kW. These results prove the validity of the proposed method to provide adequate parameters that can be used to accurately reproduce the main steady-state performance characteristics of induction motors.

We propose a method to estimate the electrical parameters of the single-, double- and triple-cage models of induction motors using manufacturer data, such as starting torque, breakdown torque, rated torque, starting current, rated current, power factor, and efficiency. The method is based on a numerical optimization problem involving the equations of the single-, double- and triple-cage steady-state models and manufacturer data available to end-users usually in form of data sheets. To validate the method, we compare theoretical with experimental results obtained for a 75 kW motor. Both types of results prove the validity and accuracy of the proposed method to assess the main performance characteristics of induction motors.