【作者】 陈红；

【导师】 曲荣海；

【作者基本信息】 华中科技大学 ， 电气工程， 2015， 博士

【摘要】 化石能源的储量危机及其引起的环境污染问题促进了新能源技术的快速发展。风能作为绿色的可再生能源,成为继火电、水电后的第三大能源,风力发电技术也是目前最具规模化开发和商业应用前景的新能源技术。发电机作为风力发电系统核心部件,其设计技术是促进风电产业发展的关键技术之一。为进一步提高发电机的功率密度、效率及可靠性,目前发电机设计技术逐步向大型化和直驱化发展。内置式永磁电机具有转矩密度大、重量轻、体积小及可靠性高等优点,成为提高大型永磁直驱发电机的功率密度的一种有效解决方案。本文主要以7MW内置式永磁直驱发电机为研究对象,对大型内置式永磁发电机的关键设计技术进行了深入探究。论文首先对大型内置式永磁电机的分析模型和电磁性能进行了深入研究。本文提出了一种内置式永磁电机的电感解析模型和计算方法,并对传统绕组函数公式进行了补充及修正。针对大型永磁发电机特殊的性能要求,文章分析和比较了分数槽集中绕组及其拓扑结构的性能,进而选择出了适用于大型内置式永磁直驱发电机的绕组型式。本文对分数槽集中绕组大型内置式永磁电机的去磁性能及影响参数进行了深入研究,提出了提高电机抗去磁能力的有效措施。同时,本文也讨论了内置式永磁电机的电磁力及振动性能,分析了定子开槽磁导、内置式转子结构、不同分数槽集中绕组槽极配合以及转子偏心对电机电磁力波的影响。本文研究了大型内置式永磁直驱发电机一体化综合设计的理念和手段。以电机的重量和成本最优为设计目标,在保证发电机输出性能的基础上,对关键设计参数进行了优化选择,进而选择出电机的初步设计方案。然后结合大型永磁直驱电机实际加工制造要求,对初步设计方案进行了细节设计和参数修正,从而得到较完善的设计方案。针对电机的设计方案,本文研究了大型内置式永磁直驱发电机的电磁性能校核方式。首先对发电机在额定运行状态时的转矩波动、电压质量及功率因数进行了核算,然后对各种损耗成分进行详细精确计算,进而核算电机效率和温升,并保证了电机绝缘及永磁材料的安全性。另外,考虑到实际风况是不断变化的,深入研究了在风电系统控制下发电机的输出性能。本文考虑了大型永磁直驱发电机在运行时可能发生的最严重的故障情况,并对大型内置式永磁直驱发电机在故障状态时的运行性能及其支撑结构的可靠性进行了较全面的核算,从而保证了发电机即使在严重故障运行时仍能保证可靠的输出。更多还原

【Abstract】 The development of new sources of energy is promoted by the energy crisis and the environmental problems. As a kind of green and renewable energy, wind energy has become the third major electric source besides coal-fire power and hydroelectric power. The wind power generation has great potential of large scale production and commercial prospect among all kinds of renewable energy. As the generator is the core component in the wind power generation system, wind generators design is one of the key technologies which boost the wind power industry. To increase the power density, efficiency and reliability, large-scale direct-drive generators are preferred for wind power generation. Interior permanent magnet (IPM) machines, characterized by high torque density, light weight, compact size and high reliability, could be strong candidates for large-scale direct-drive wind generators. This thesis conducts an in-depth research into the key technologies of large-scale IPM generators by designing a7MW direct-drive IPM generator.Firstly, the analytical model and performances of large-scale IPM generators are studied. An improved analytical model to calculate the inductances of the interior permanent magnet (IPM) machine is presented, equipped with either fractional slot concentrated windings or distributed windings. Subsequently, research on the FSCW and the machine topology is carried out to find the best winding configuration for large-scale direct-drive IPM generators. The demagnetization characteristic of IPM generator and the influencing factors are analyzed, and a method is proposed to improve the anti-demagnetization ability. The electromagnetic forces and the vibration characteristics are also studied, considering the influences of the air gap permeance harmonics due to slot opening, the IPM rotor topology, the slot-pole combinations and the rotor eccentricity.An integrated design method is developed for large-scale direct-drive IPM generators. Taking the optimal weight and cost as design object, the key design parameters are optimized, including the aspect ratio, the pole number, the tooth width, and the size and grade of the permanent magnets. After the preliminary design, the detailed design and parameter modification are conducted to achieve a complete design which meets the processing and assembly requirements.An approach to check the electromagnetic performance of large-scale direct-drive IPM generators is presented based on the aforementioned generator design. Above all, the torque ripple, voltage quality and power factor are checked at rated condition. Furthermore, the losses and the efficiency are accurately calculated, and the temperature rise is also reviewed to ensure the safety of the insulation and the permanent magnets. Finally, the output performance of the generator is analyzed in view of the changing wind condition.The worst fault condition of a large-scale direct-drive wind generator is considered in the output performance analysis and the strength check of the supporting structure. It reveals reliable power output performance is guaranteed even at serious fault conditions.更多还原