【作者】 郝鹤；

【导师】 沈建新；

【作者基本信息】 浙江大学 ， 电气工程， 2013， 博士

【摘要】 高速电机具有功率密度高、效率高、结构简单等诸多优点,已广泛应用在高速加工中心、飞轮储能、电辅助涡轮增压器、空气压缩机、高速离心机等诸多领域。高速永磁无刷电机诸多关键问题也得到越来越多的关注,例如电磁损耗分析及其抑制、温升分析及其减小措施、无位置传感器控制方法等,正日益成为国内外的研究热点。本文主要以表贴式高速永磁无刷电机为研究对象,对影响其电磁性能的诸多因素,如定子裂比、定转子结构形式、永磁体的选择等进行分析,采用多场交叉分析方法对高速电机的转子损耗和温升计算及其削弱方法进行深入分析,并提出一种无位置传感器控制策略。本文首先研究了一种基于多场分析的高速电机综合设计方法。研究了随着高速电机定子裂比的减小,电机的转矩密度和电磁损耗的变化规律；研究了不同定转子结构形式对电机电磁性能的影响,重点分析了参数变化时转子损耗的变化情况。此外,本文还研究了永磁体材料、超前触发控制方式等对电机电磁性能、转子损耗及转子动力学特性的影响。接着,本文提出在转子护套上开周向浅槽来减小高速电机转子损耗并降低转子温升,同时不影响转子护套的机械强度。采用有限元方法深入分析研究高速电机转子护套开周向浅槽对转子涡流损耗、风摩损耗及温升等的影响；同时,分析了转子护套开槽前后的转子护套应力变化情况。通过上述分析,证明该方法的有效性。然后,本文针对表贴式高速永磁无刷直流电机,提出了一种基于磁链观测器法的全硬件实现的无位置传感器控制策略。本控制策略不受二极管续流的影响,且可以为超前触发控制策略提供连续的转子位置信号,合高速工况下使用。此外,针对内嵌式永磁无刷电机电感随转子位置变化的特点,提出了一种改进的磁链观测器,进行了理论分析与实验验证。最后,在前几章研究的基础上,设计制造了电辅助涡轮增压器用高速电机及其驱动器的样机系统,并对样机系统进行了对比空载实验和负载实验。实验结果表明,高速电机本体及其无位置传感器控制方法的设计正确,系统运行稳定、可靠。更多还原

【Abstract】 Due to the merits of high efficiency, high power density and simple system construction, high-speed motors have found extensive applications in many industry areas, such as high-speed machining center, flywheels, electric-assisted turbo chargers, compressors, centrifuges and so on. The high-speed permanent magnet brushless motor has attracted extensive attentions, for example, on the aspects of electromagnetic power losses and relevant reduction methods, excessive temperature rise and countermeasures, and sessorless control methods.This dissertation mainly focuses on the surface mounted permanent magnet brushless motor, and analyses the influencing factors on the machine electromagnetic performance, such as the stator split ratio, the stator and rotor structures, the magnet configurations, and so on. Multi-fields analyse will be adopted to calculate the rotor power losses and temperature rise, and to investigate the methods to reduce the power losses and the temperature rise. And, a new sensorless control strategy will also be presented.Firstly, a multi-fields analysis-based design method for the high speed motor is presented in this dissertation. Variation of the electromagnetic performance of the high speed motor with different stator split ratios, and stator and rotor structures is studied. Moreover, influences of the permanent magnet configurations and phase-advancing control on the machine performance and the rotor dynamics are also analyzed in this paper.Secondly, the finite element method is used to analyze the influence of rotor sleeve circumferential grooves on the rotor eddy-current loss, air friction loss and temperature rise. Also, the retaining sleeve stress before and after grooving is comparatively analyzed. All studies verifies that the circumferential grooves on the retaining sleeve can effectively reduce the rotor power loss and temperature rise, but hardly deteriorates the retaining sleeve strength.Then, a sensorless control method by which high-resolution rotor position information is estimated and used for phase-advancing operation of a high-speed surface mounted permanent magnet brushless dc motor is proposed. The proposed sensorless control approach uses hardware to observe the rotor flux vector which is excited by the permanent magnets. It can provide the rotor position which is the same as the phase angle of the observed flux vector, and the method is suitable for phase-advancing control under the high-speed condition. Whilst, for interior permanent magnet (IPM) motors, the sensorless control strategy is improved by modifying the rotor flux observer, which considers the rotor saliency.Subsequently, an experimental system of the sensorless high-speed surface-mounted permanent magnet brushless dc motor, which is associated with an electrical-assisted turbocharger, is set up. Both no-load and on-load experiments are taken, proving that the multi-fields based motor design and the proposed sensorless control strategy are workable and reliable.更多还原