【作者】 夏冰；

【导师】 沈建新； 金孟加；

【作者基本信息】 浙江大学 ， 电机与电器， 2011， 硕士

【摘要】 随着能源和环境问题的日益突出,新能源逐渐成为了人们关注的焦点。而风电作为现阶段最成熟最具商业化发展前景的新能源产业之一,得到了各国政府及各大公司的高度重视。特别是小型风力发电系统,机动性高,使用灵活,不仅在牧区、渔船、海岛等偏远地区有着广阔的应用前景,在城镇照明、监控等小功率用电设备上也有着无可比拟的优势。盘式电机结构简单紧凑,体积小且转矩密度高,特别是双外转子无定子铁芯的盘式永磁电机,消除了齿槽转矩和定子铁耗,启动转矩低,效率高；外转子上可以直接安装风机,系统简单可靠,适合作为垂直轴直驱式的风力发电机。由于采用轴向磁场的盘式电机结构不同于传统的柱式电机,分析时需要做三维(3D)仿真,给电机电磁性能的计算带来了困难。本文通过研究盘式电机的基本理论,分析其磁场分布特点,提出了一种分段式二维(2D)有限元的计算方法,将盘式电机在半径方向上分成多段,以建立2D简化模型来模拟3D磁场分布,并计算电机的反电势,从此提高了盘式电机仿真计算的效率。同时,在2D简化模型的基础上,本文还推导了双外转子无定子铁芯的盘式电机磁场分布的解析表达式,并计算了无槽式集中绕组的绕组系数,为这种结构电机的设计和优化提供了一种简便的途径。论文还将3D有限元仿真的结果与分段式2D有限元和2D解析法的计算结果进行了对比,以验证2D有限元法和2D解析法的准确性。最后制造了一台双外转子无定子铁芯的盘式永磁电机的样机,并测试了样机的各项性能。样机空载性能的测试,验证了分段式2D有限元法和解析法的正确性和高效性；样机负载性能以及温升测试表明,样机输出稳定,电压调整率低,效率高,温升低,能够长期稳定运行,适合作为小型垂直轴风力发电机。更多还原

【Abstract】 With the growing concerns of the energy and environment issues, renewable energy is becoming the focus of the public. As one of the most matured technologies of the renewable energy industry, wind power is getting great attention from various governments and companies. Small-scale wind power system, with its high mobility and flexibility, has broad application prospects not only in the pastoral areas, fishing boats, islands and other remote areas, but also in cities and towns for public lighting and monitoring devices.Axial flux permanent magnet (AFPM) machines have the merits of compact structure and high torque density. Since the absence of stator core eliminates the cogging torque and stator coreloss, the double-rotor single-coreless-stator AFPM wind generator is able to start at a low torque and operate with high efficiency, and is a most suitable candidate for vertical-axis direct-drive wind power system. Because of the different structure from traditional radial flux machines,3-dimensional (3D) field analysis is needed for the AFPM machines, which brings difficulties in calculating the electromagnetic feature of the AFPM machines.By studying the basic theories and the flux distribution of AFPM machines, a segmental 2-dimensional (2D) finite-element method (FEM) is proposed. The method is to cut the AFPM machine in the radial direction into segments, and build up simplified 2D models to simulate the 3D flux distribution and calculate the back EMF of the machine, so as to improve the simulation efficiency. And then, an analytical method is presented based on the 2D model, and formulas of the flux density in the double-rotor single-coreless-stator AFPM machine is deduced. Besides, the coil factor for non-overlapping coil in slotless stator is also calculated, which provides a simplified method to design and optimize this kind of machine.3D FEM is also carried out to validate the accuracy of the two 2D methods.Finally, a prototype of double-rotor single-coreless-stator AFPM machine is manufactured and tested. Through the no-load test of the prototype, the segmental 2D FEM and 2D analytical method are confirmed to be both efficient and accurate. Load test and the temperature rise test indicate that the prototype has a satisfactory performance with high efficiency, low voltage regulation and low temperature rise. The prototype machine can be used for long-term stable operation.更多还原