高速永磁同步电机在多物理场和变流器约束下的设计

Design of High-Speed PMSM Considering Multi-Physics Fields and Power Converter Constraints

高速电机中多物理场是强耦合的,其影响是甚至相互矛盾的。因此,高速电机的设计受到多物理场的强制约。此外,变流器的电压和电流都受限,由此也制约了高速电机的设计。当电机功率较大时,所有这些约束变得更加显著,因此较难获得一个很好的优化设计方案。该文以一台350kW、13.5kr/min的大功率高速内置式永磁同步电机作为案例,阐述其设计方法与优化过程。针对不同工况,研究电机永磁磁链与绕组电感的匹配设计,以确保变流器的电压和电流限制均得到满足。之后,通过有限元的手段研究相关的电机设计要点,特别是考虑电磁特性、机械应力和动力学特性的转子拓扑结构;也通过计算流体动力学(CFD)手段研究电机的热性能。由此可实现完整的高速电机多物理场设计。

Multi-physics fields inside high-speed electrical machines are strongly coupled and may even conflict with each other.Therefore,design of the high-speed machines is extremely constrained by these fields.Moreover,power converters have limited current and voltage,by which the machine design is also constrained.All these constraints become further significant if the machines are of high power.Therefore,it is challenging to achieve a feasible solution of machine design.As a study case,design and optimization of a 350kW and 13.5kr/min interior permanent magnet synchronous motor(PMSM)is presented in this paper.Principal of matching the permanent magnet flux linkage with the winding inductances for various operation conditions is investigated,so that both the voltage and current limits of the power converter can be satisfied.Then,related design aspects are addressed,especially,the rotor configuration considering the electromagnetic performance,mechanical stress and rotor dynamics is studied with finite element methods(FEM),and the thermal behavior is studied with computational fluid dynamics(CFD),demonstrating the comprehensive procedure of multi-physics design.