【作者】 曹继伟；

【导师】 陈清泉； 李立毅；

【作者基本信息】 哈尔滨工业大学 ， 电气工程及其自动化， 2014， 博士

【摘要】 高温超导电机具有高功率密度、高效率的优势，是高温超导材料应用的一个重要领域，可以广泛应用于船舶推进、风力发电、飞轮储能等多个领域中，具有重要的学术研究价值和经济应用前景。现有的高温超导电机多利用高温超导线圈作为转子的励磁线圈，以提高电机磁负荷的方式来提高电机的功率密度，这种结构的高温超导电机的冷却温度低（10K-50K），冷却介质为液氖或冷气氦，且冷却成本高、冷却结构复杂。本文针对现阶段高温超导电机的研究现状和高温超导线材的性能水平，提出一种具有高温超导电枢绕组的高温超导永磁同步电机系统，开展其高温超导线材及定子超导电枢绕组特性的研究，突破高温超导线圈在复杂磁场条件下载流能力下降、超导永磁同步电机设计和制造的关键难点问题。本文首先针对普通永磁同步电机极限输出转矩的理论和试验进行分析，揭示了永磁同步电机极限功率与其电、磁负荷之间的影响关系，得到了限制永磁同步电机输出特性的主要因素不是铁心材料的饱和，而是由于定子电枢绕组的损耗。因此，本文提出利用高温超导线圈代替普通的铜绕组线圈作为定子电枢绕组，以提升永磁同步电机的功率密度与效率。将高温超导线材/线圈的载流特性规律引入到传统电机学理论中，通过数值解析方法得到高温超导线圈表面磁场密度，揭示了高温超导永磁同步电机定子电枢绕组临界电流的影响因素，进而得到了超导电枢绕组类同步电机相似性类比方法。通过铜绕组超导永磁同步样机的试验和有限元仿真结果，验证了超导电枢永磁同步电机类比方法的正确性，为高温超导永磁同步电机的研制奠定了理论基础。针对YBCO高温超导线材在复杂变化磁场环境下的交流载流特性进行了研究。在美国Superpower公司的SCS12050超导线材性能的基础上，建立了高温超导线材复杂磁场条件下临界电流测试平台。通过此平台分别对YBCO高温超导线材进行了不同幅值的恒定外加磁场、不同幅值和频率正弦磁场条件下的线材交流载流特性进行了试验研究，通过试验数据，揭示了高温超导线材在复杂磁场环境中的交流载流特性规律，为高温超导线圈的特性及高温超导电机的研发奠定了试验基础。分析高温超导电枢绕组永磁同步电机定子槽内的磁场分布特性，针对这种分布特性，提出了一种磁场调制方法，可以有效减小高温超导线圈表面垂直磁场的分布，从而提高高温超导电枢绕组的载流能力，进一步提升高温超导永磁同步电机的功率密度。建立不同结构、不同尺寸参数的高温超导绕组磁场调制方法的有限元模型，通过有限元软件的分析和计算，揭示高温超导线圈磁场调制方法的结构参数与线圈表面磁场、槽漏磁场之间的影响规律。磁场调制方法的仿真数据表明，该方法可以降低高温超导线圈表面垂直磁场4倍左右。根据分析计算的数据，研制高温超导线圈和相应的磁场调制作用的导磁片，通过在液氮温度（77K）下的测量，验证了具有磁场调制方法的超导线圈临界电流提升了35%，在不增加额外的制冷成本和线材成本的条件下，提升了高温超导线圈的性能。研制一套等效高温超导电机槽内磁场环境的高温超导线圈测试系统，通过该测试系统测试了绕制的12个高温超导线圈，测试结果表明绕制完成的高温超导线圈在液氮温度下（77K）的临界电流均为250A左右，达到了预先的设计指标。通过上述理论和试验研究，揭示具有高温超导电枢绕组的超导永磁同步电机电磁功率同其电、磁负荷之间的规律，提出具备高电枢电流承载能力的超导同步电机电负荷选取策略及超导电枢绕组永磁电机相似性类比方法；明确高温超导线材/线圈在复杂磁场条件下的载流能力规律，提高高温超导电枢绕组的载流能力，突破超导同步电机高温超导电枢绕组的关键技术，推进高温超导材料在工业领域内的应用。更多还原

【Abstract】 High temperature superconducting (HTS) motor has many merits: high power density, high torque density, little volume, light weight, so it would be an important application field of high temperature superconductor because it can apply in the ship thrust, wind power, flywheel energy storage, ects. HTS motor has high research value and market prospect. Now, HTS motor mostly applied the superconducting magnets as the excitation magnets of the motor rotor which improves the power density from the higher magnetic load (air flux density). This structure need lower cool temperature that is cooled by liquid neon or air helium, so its cost is high and its cool structure is complicate. This paper presents a novel HTS permanent magnet synchronous motor with superconducting armature coils, researches the characteristic of HTS wire and armature coils, makes a breakthrough in the field of HTS wire carrying ability with complicate magnetic field and HTS motor design, manufacture.Firstly, based on the normal permanent magnet synchronous motor (PMSM) theory and test, this paper reveals the influence between the PMSM ultimate power and electrical, magnetic load, and obtains main factor which influences the characteristic of PMSM output is not the the saturation of iron, but is the the copper loss of stator winding. Therefore, this paper prensents the superconducting coils replaces the copper coils as the stator armature winding for improving the output characteristic of PMSM. Then, the superconducting wire’s carrying ability is introduced to traditional motor theory, the influencing law between PMSM armature winding current and HTS wire’s critical current are revealed based on HTS wire’s surface flux density calculated by numercial analysis, then the similarity method of HTS PMSM with superconducting armature winding is obtained. Through the experiment result of HTS copper prototype and finite element simulation, the accuracy of the similarity method is verified.Secondly, the paper researches the YBCO superconducting wire’s carrying ability that is the key part of HTS motor. Based on the characteristic of SCS12050HTS wire which produced by American Superconducting. INC, the superconducting wire critical current test instrument which could test critical current in complicate magnetic field is established. With the test instrument, the superconducting wire alternating critical current in the condition of different extra constant magnetic field, different amplitude and frequecy magnetic field is measured. Through the measure data, the superconducting wire alternating current carrying ability is revealed. Those carrying ability rules could be the test basement of HTS motor reserach.Thirdly, this paper analyzes the magnetic field distribution of superconducting armature winding in motor stator slot. So this paper presents a novel magnetic screening method for decreasing the perpendicular magnetic density on the superconducting coils surface. This method could improve the superconducting coils’ carrying ability and the power density of HTS motor. The magnetic screening method ’s different shapes models are established for analyzing its effects by finite element method (FEM), its different structure parameters are also analyzed in the same method. Then, the influence law between superconducting coil surface magnetic density and the magnetic field modulation parameters is revealed by the FEM software. From the FEM analysis and loss result, the magnetic field value could be decreased four times through the magnetic field modulation method. Then the ferromagnetic slabs for magnetic field modulation are manufactured, the superconducting coils with or without ferromagnetic slabs are tested in liquid nitrogen temperature (77K). The test result proves the magnetic screening method could increase35%critical current. So the characteristic of superconducting coils would be improved without no additional extra cooling and wire cost.Finally, an equivalent HTS armature winding test system whose magnetic field could be equal to the magnetic environment of HTS armature winding in the HTS motor is established. This test system measures twelve HTS armature coils. The result achieves the design value.Through those researches, the influence law between electromagnetic power of the HTS PMSM with superconducting armature winding and electrical, magnetic load is revealed. This paper presents the electrical load selection method of HTS PMSM with large armature current, and presents the similarity design method of the HTS motor with superconducting armature winding. The current ability of superconducting wire and coil in complex magnetic field is tested, and the superconducting armature winding critical current is improved through a novel magnetic field modulation method. Those research content make a breakthrough in key technology of superconducting armature winding, promote the industry application of HTS wire.更多还原