【作者】 孙毅；

【导师】 沈建新； 王云冲；

【作者基本信息】 浙江大学 ， 电气工程， 2021， 博士

【摘要】 永磁辅助同步磁阻电机具有高功率密度、高效率、调速范围广、无稀土或少稀土等诸多优势,受到国内外学者广泛地关注。本文研究了永磁辅助同步磁阻电机程序化优化设计方法,其特点是集电机自动化建模、绕组自动化分相、电机参数自动化设计和有限元计算于一体。首先,本文研究了一种基于槽星形图的对称绕组分相理论,并给出了对称绕组磁动势的计算方法。对称绕组分相理论给出了对称绕组可以分相的充分必要条件。借助绕组分相公式得到了对称绕组磁动势谐波的解析表达式。运用对称绕组分相理论实现了绕组程序化自动分相。其次,给出了永磁辅助同步磁阻电机的数学模型,将其作为永磁辅助同步磁阻电机程序化优化设计的理论依据。为了兼顾电机的电磁性能、机械性能与可加工性,提出了磁桥有源饱和的概念,并详细地分析了有源饱和技术的原理。通过有限元仿真验证了运用有源饱和技术可以补偿电机由磁桥变厚而带来的电磁性能损失。此外,相比于永磁体放置在磁障末端,永磁体放置在磁障中间更有利于转子磁桥饱和。进一步,结合电机的基波模型与有源饱和技术,确定了转子上永磁体放置的合适位置和永磁体最优的形状。再次,给出了永磁辅助同步磁阻电机程序化优化设计方法的具体实施步骤。永磁辅助同步磁阻电机优化设计可以看作为一个多变量、多目标的优化问题,其多目标优化问题可以转化为两个低维单目标子问题。以永磁辅助同步磁阻电机的基波模型、有源饱和技术、最优永磁体位置与形状为基础,研究了一种基于有限元计算的解析优化算法,将其作为子问题I的求解算法。介绍了带精英策略的遗传算法、粒子群算法与模式搜寻算法,将其作为子问题II的求解算法。在求解子问题II时,综合优化结果与计算效率两个方面,模式搜寻算法表现优于带精英策略的遗传算法与粒子群算法。因此,采用解析优化算法求解子问题I,并运用模式搜寻算法求解子问题II。最后,通过基于有限元的优化程序优化了9个不同的电机,包括了不同的绕组形式、不同的功率等级、不同极槽配合、不同的磁障层数与不同的永磁体类型。从优化过程来看,整个优化收敛过程仅需要少量的有限元计算。从优化结果来看,优化后的9个电机电磁性能均满足设计要求。即使不借助定转子斜槽、不对称转子结构、定子槽数与转子磁障层数配合等方法,具有对称转子结构的永磁辅助同步磁阻电机经过优化后也可以得到很低的转矩脉动。通过7.5k W和18.5k W的铁氧体辅助同步磁阻电机实验验证了永磁辅助同步磁阻电机程序化优化设计方法的正确性与有效性。对比了相同功率下的感应电机、铁氧体与稀土永磁体辅助同步磁阻电机三类电机的成本与性能,并列举了程序化优化设计的永磁辅助同步磁阻电机系列化产品。更多还原

【Abstract】 PM-Assisted synchronous reluctance machines(PMASyn RMs)have received a wide attention,due to various inherent merits of high power density,high efficiency,wide speed range,no or little rare earth,etc.In this thesis,the programmable optimal design of PMASynRMs is studied,which is characterized by the integration of automatic modeling,winding distributions,optimization and FEA calculation.Firstly,the theory of symmetric winding distributions based on the star of slots is studied and a general method for winding MMF harmonic analysis is presented.This theory gives the sufficient and necessary conditions of winding feasibility,and analytical results of symmetric winding MMF are obtained by the winding distribution formula.This theory is applied in automatic winding distributions by the computer program.Secondly,the analytical model of PMASyn RMs is presented,which is the theoretical ground of the programmable optimal design.In order to keep the right balance among electromagnetic performance,mechanical performance and manufacturability,the concept of the active saturation for the flux bridge is proposed,and the principle of the active saturation method(ASM)is discussed in detail.ASM can be implemented in such synchronous reluctance machines(Syn RMs)with enhanced flux bridges to compensate the resultant electromagnetic performance loss,which is validated by 2D FEM.Moreover,compared with the End-ASM Syn RM that the permanent magnet placed at the end of the flux barrier,the flux-bridge saturation of the Middle-ASM Syn RM that the permanent magnet placed in the middle of the flux barrier is more severe.Furthermore,the proper position and the optimal shape of the permanent magnets in the rotor are determined based on both the analytical model of PMASyn RMs and ASM.Subsequently,the implementation of the programmable optimal design for PMASynRMs is presented.The optimization for PMASyn RMs can be regarded as multi-parameter and multi-object optimization problems(MOOPs),which can be transformed into two lowdimensional single-object optimization sub-problems(SOOPs).Based on the analytical model of PMASyn RMs,ASM,the proper position and the optimal shape of the permanent magnets in the rotor,the analytical model algorithm based on FEA calculation is studied,which is used in solving the sub-problem I.The Elitist model based Genetic Algorithm(EGA),Particle Swarm Optimization(PSO)and Pattern Search(PS)are introduced,which are used for solving the sub-problem II.When solving the sub-problem II,it is revealed that the optimization with PS is superior,in aspects of optimized machine performance and optimization efficiency,compared with that of E-GA and PSO.Therefore,the analytical model algorithm is used for solving the sub-problem I,and PS is used for solving the sub-problem II.Finally,nine different machines are optimized based on 2D FEM calculation,including different winding types,power levels,slot/pole combination,number of flux barriers and types of permanent magnets.From aspect of optimization convergence process,only a small amount of 2D FEM calculation is needed.From aspect of optimization results,the results of nine optimized machines are satisfied.The torque ripple of the optimized PMASyn RMs with symmetrical rotor structure is also low without the stator chording and rotor skewing,asymmetric flux barrier arrangement and optimal combination of the number of rotor flux barriers and stator slots.7.5k W and 18.5k W prototype machines are manufactured and tested to validate the programmable optimal design of PMASyn RMs.The cost and performance of the induction machines,ferrite and rare earth-assisted Syn RMs with the same power are compared.Moreover,the series products of PMASyn RMs by method of the programmable optimal design are presented.更多还原