Multi-objective Design Optimization of an IPMSM Drive System Based on Loss Minimization Control Strategy

To enhance the optimization and control efficiencies of the interior permanent magnet synchronous motor (IPMSM) drive system for electric vehicles (EVs), an improved multi-objective design optimization strategy at the system level is proposed in this paper. To handle the high dimensional and nonlinear problems for searching Pareto optimal solutions, the multi-level optimization algorithm with approximate models is utilized, by which the computational cost can be greatly reduced. In terms of the typical specifications and requirements of EVs, the maximum torque, minimum torque ripple, and minimum speed overshoot are set as the optimization objectives. For further improving the optimization accuracy and search speed, the objective of minimum loss is achieved through the loss minimization control algorithm instead of being solved in each optimization level, by which the system efficiency is also promoted. Experimental and numerical results show that the proposed approaches can effectively solve the design optimization issues of electric drive systems, and enhance the static and dynamic system performance.