Topology optimisation of PMSM rotor for pump application

This paper proposes a design optimization procedure of a PMSM rotor. In the process of optimization, the shape and the size of the permanent magnet is considered constant while the distribution of electric steel and voids (air) in the rotor are variables contributing to the final objective. For the gradient search the “Method of Moving Asymptotes” algorithm is applied to the rotor design of an internal permanent magnet synchronous motor for a circulation pump. The objective of the optimisation is to improve the torque of the machine with any given magnet placement or shape. The optimisation method takes into account the inherent mesh dependency of the topology optimization process, and dynamic constraints are applied ensuring designs with favourable cogging and ripple torque characteristics. The design method is carried out for various magnet sizes and placements, showing the ability of the algorithm to find valid solutions in the search space.