Optimization Procedure for IPM Motors by Changing the Rotor Structure

Abstract

The paper has developed an optimization procedure to design the rotor lamination and magnetic sizes. The average torque is improved by changing the thickness of the outer bridge and magnetic width. Various metamodels with the best prediction performance generated for each of the multi-objective functions and constraints have been selected. By applying a multi-objective genetic algorithm, several optimal solutions have to be considered to compare with those of the initial model. Hence, the multi-objective optimization method for designing the interior permanent magnet (IPM) motor is presented to obtain the high reliability and maximum torque. This development allows to estimate the back electromotive force (EMF), magnetic flux density and electromagnetic torque. In addition, the torque ripple evaluated via  the analytical Matlab program is coupled to the finite element method and genetic algorithm optimization. Rotor laminations are finally stamped and assembled into the motor to verify the EMF under the rated load and no load test.