Topological design of nonlinear permanent magnet synchronous machines based on material-field series-expansion

The permanent magnet synchronous machine (PMSM) is a complex electromagnetic system with high nonlinearity, which produces great challenges in the system’s topological design. This paper presents an effective topology optimization method for PMSMs to seek excellent working performances based on the material-field series-expansion model. This model represents the motor topology by using a reduced series-expansion of the material field, which leads to a significant reduction in the design variables. The optimization problem of PMSMs is solved using the Kriging-based programming to avoid the tedious sensitivity analysis and difficulties presented by local minima. Complex objective functions involving the nonlinear electromagnetic field and ferromagnetic materials can easily be handled in the optimization procedure. Numerical examples, including the total magnetic potential energy minimization problem and the torque maximization problem for PMSMs, are given to demonstrate the validity and effectiveness of the proposed method.