混合动力汽车用轴向磁场调制型无刷双转子电机的研究

发布时间：2019-06-11 04:14

【摘要】：混联式混合动力汽车以其高燃油经济性和优良的驾驶性能受到广大汽车厂商和消费者的青睐。目前最成功的混联式混合动力汽车日本丰田普锐斯采用基于行星齿轮机构的电控无级变速装置,可使内燃机不依赖于路况始终工作在燃油高效区,提高了汽车的燃油经济性,降低了尾气排放。基于纯电机方案的电控无级变速装置可实现相同的功能,同时具有结构紧凑和控制灵活的优势,是混合动力汽车领域寄予厚望的发展方向。然而,早期的有刷式电机方案需要电刷滑环馈电,降低了系统的可靠性。本文提出了一种轴向磁场调制型无刷双转子电机(Axial-Magnetic-Field-Modulated Brushless Double-Rotor Machine,AMFM-BDRM),该电机与常规永磁同步电机相结合,构成轴向磁场调制型无刷复合结构电机方案。该无刷式电机方案解决了有刷式电机方案电刷滑环结构可靠性差、内转子散热困难、旋转绕组动平衡难以保证等问题,且其扁平型结构提高了轴向空间利用率,在转矩密度上具有潜在优势。本文所做工作主要包括以下几个部分:首先,研究了轴向磁场调制型无刷双转子电机的工作原理和基本电磁设计方法。采用解析分析方法研究了磁场调制作用对气隙磁密分布的影响规律,建立了轴向磁场调制型无刷双转子电机转速解耦及转矩定比传递的数学模型。推导了轴向磁场调制型无刷双转子电机的齿槽转矩,并探讨了永磁调制谐波和定子电枢调制谐波的相互作用对转矩波动的影响规律。基于麦克斯韦应力张量法并结合三维有限元仿真,研究了定子、永磁转子极对数和导磁块个数的匹配对电机不平衡轴向磁拉力的影响规律,给出了该类电机的基本电磁设计方法。其次,为解决三维有限元分析模型复杂的问题并提高电机优化设计的灵活度,建立了基于等效面电流法的简化二维解析模型和考虑定子齿槽效应的精确二维解析模型。考虑电机内磁场沿径向分布的相似性规律,建立了基于电枢绕组等效面电流法的简化二维解析模型,推导了空载反电势、电磁转矩和轴向磁拉力的解析表达式。建立了考虑定子齿槽效应的二维精确解析模型对前述解析表达式进行修正,并与三维有限元仿真结果进行对比,论述了解析分析模型的精度和适用范围。再次,研究了轴向磁场调制型无刷双转子电机的功率因数、单侧轴向磁拉力、电机不对称和涡流损耗等特殊电磁问题。针对电机功率因数偏低的问题,探讨了每相绕组串联匝数、直径比和内功率因数角等参数对功率因数的影响规律,提出了有效提高功率因数的方法。基于麦克斯韦应力张量法研究了电机结构参数对轴向磁拉力的影响规律。评估了永磁转子平移、倾斜和两侧磁钢不对称等电机不对称情况对气隙磁密、轴向磁拉力、空载反电势和电磁转矩的影响。研究了损耗构成及其所占比重,分析了双转子转速对永磁体涡流损耗的影响规律,探讨了永磁体分块方式对永磁体涡流损耗的抑制效果。针对现有方案功率因数低、永磁体涡流损耗大的问题,提出了两种改进型结构方案:永磁转子改进型结构方案和双转子改进型结构方案,并评估了方案的有效性。最后,设计并制造了一台轴向磁场调制型无刷双转子电机的样机,搭建了实验平台并进行了实验测试。通过对样机空载反电势、空载损耗、输出转矩、功率因数和效率的测试与分析,验证了理论分析的正确性和可行性。通过混合动力汽车工况模拟实验,验证了电机具有转速调节和转矩定比传递的功能,为轴向磁场调制型无刷双转子电机在混合动力汽车中的应用奠定了理论和技术基础。
[Abstract]:The high-fuel economy and excellent driving performance of the hybrid-type hybrid vehicle are favored by the automobile manufacturers and consumers. At present, the most successful hybrid-type hybrid electric vehicle, Toyota Prius, adopts an electric-controlled stepless speed-changing device based on a planetary gear mechanism, so that the internal-combustion engine can not be always operated in the fuel efficient area according to the road condition, and the fuel economy of the automobile is improved, and the emission of the tail gas is reduced. The electric control stepless speed change device based on the pure motor scheme can realize the same function, and has the advantages of compact structure and flexible control, and is the development direction of the mixed power automobile. However, the early brush-type motor scheme requires a brush slip ring to feed, which reduces the reliability of the system. In this paper, an axial magnetic field-modulated brushless double-rotor machine (AMFM-BDRM) is proposed, which is combined with a conventional permanent-magnet synchronous motor to form an axial magnetic field-modulated brushless composite structure motor scheme. The brushless motor scheme solves the problems of poor reliability of the brush slip ring structure of the brush type motor scheme, difficulty in heat dissipation of the inner rotor, difficulty in ensuring the dynamic balance of the rotating winding, and the like, and the flat structure of the brushless motor scheme improves the axial space utilization rate and has the potential advantage in the torque density. The work of this paper mainly includes the following parts: firstly, the working principle and the basic electromagnetic design method of the axial magnetic field modulation type brushless double-rotor motor are studied. The influence of the magnetic field modulation on the magnetic density distribution of the air gap is studied by the analytical method, and the mathematical model of the rotational speed decoupling and the torque constant ratio transfer of the axial magnetic field modulation type brushless double-rotor motor is established. The cogging torque of the axial magnetic field modulation type brushless double-rotor motor is derived, and the influence of the interaction of the permanent magnet modulation harmonic and the stator armature modulation harmonic on the torque fluctuation is discussed. Based on the Maxwell stress tensor method and combined with the three-dimensional finite element simulation, the influence of the matching of the number of pole pairs of the stator, the permanent magnet rotor and the number of the square blocks on the unbalanced axial magnetic tension of the motor is studied, and the basic electromagnetic design method of the motor is given. Secondly, in order to solve the complicated problem of the three-dimensional finite element analysis model and to improve the flexibility of the motor optimization design, a simplified two-dimensional analytical model based on the equivalent surface current method and an accurate two-dimensional analytical model considering the effect of the stator tooth space are established. Considering the similarity of the magnetic field in the motor along the radial distribution, a simplified two-dimensional analytical model based on the equivalent surface current method of the armature winding is established, and the analytical expression of the no-load reverse potential, the electromagnetic torque and the axial magnetic force is derived. In this paper, a two-dimensional accurate analysis model, which takes into account the stator tooth space effect, is established to correct the analytical expression, and compared with the three-dimensional finite element simulation results, the accuracy and the application range of the analytical model are discussed. Thirdly, the special electromagnetic problems such as power factor, single-side axial magnetic tension, asymmetric motor and eddy current loss of the axial magnetic field-modulated brushless double-rotor motor are studied. In view of the low power factor of the motor, the influence of the number of turns, the diameter ratio and the internal power factor angle of each phase winding on the power factor is discussed, and the method of effectively improving the power factor is put forward. The influence of motor structure parameters on axial magnetic tension is studied based on Maxwell's stress tensor method. The effects of non-symmetry of the motor on the magnetic density, axial magnetic tension, no-load reverse potential and the electromagnetic torque of the permanent-magnet rotor, such as the translation, the tilt and the non-symmetry of the magnetic steel on both sides, are evaluated. The influence of the double rotor speed on the eddy current loss of the permanent magnet is analyzed, and the effect of the block mode of the permanent magnet on the eddy current loss of the permanent magnet is discussed. In view of the problems of low power factor and large eddy current loss of the permanent magnet, two improved structure schemes are proposed: the improved structure scheme of the permanent magnet rotor and the improved structure of the double rotor, and the effectiveness of the scheme is evaluated. Finally, a prototype of an axial magnetic field modulated brushless double-rotor motor was designed and manufactured, and the experimental platform was built and the experiment was carried out. The correctness and feasibility of the theoretical analysis are verified by the test and analysis of no-load reverse potential, no-load loss, output torque, power factor and efficiency of the prototype. The function of the motor with the speed regulation and the torque constant ratio transmission is verified by the simulation experiment of the mixed power automobile working condition, and the theoretical and technical basis is laid for the application of the axial magnetic field modulation type brushless double-rotor motor in the hybrid vehicle.
【学位授予单位】：哈尔滨工业大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：U469.7

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