定转子双永磁激磁高转矩密度离网式直驱风力发电机系统研究

Wind power generation is considered to be a promising solution to energy crisis and global warming. On several special occassions, stand-alone wind power generation is becoming more and more important. Direct drive wind power generator system can get rid off the nuisances arising from the mechanical gearbox, however, it suffers from the extremely low power/torque density. This project proposes a novel dual-permanent-magnet-excited (DPME) wind power generator, which is based on the bi-directional field modulation effect. By effectively increasing the permanent magnetic load, the torque density of the proposed machine is expected to be dramatically improved compared with its traditional counterparts. Moreover, its simple mechanical structure allows it can be commercialized conveniently. This project aims at completing and consolidating the proposed theory on bi-directional field modulation effect, after that, studying the proposed DPME stand-alone wind power generator system, which includes the machine topology, machine analysis method, machine multi-object optimal design, machine mathematical modeling and maximum generation power point tracking control, finally, building up 50 kW prototype, and conducting experimental tests. As for the torque density, we will try to achieve the level of 100 kNm/m^3 by using optimal electromagnetic design.

风力发电是转变能源利用方式、对抗能源危机和全球暖化的重要途径，而发展离网式风力发电在很多特殊场合日益显出其重要性。直驱风力发电机系统可摆脱传统机械齿轮箱带来的种种弊端，但过低的转矩/功率密度使得其在当前的应用中存在诸多问题。本申请项目提出了一种基于双向磁场调制效应的定转子双永磁激磁直驱风力发电机。通过有效地增加永磁磁负荷，该型发电机的转矩密度有望得到大幅提升。此外，其简单的机械结构也为今后产业推广创造了有利条件。本申请项目旨在对所提出的双向磁场调制效应理论进行整理和完善，并结合离网式直驱风力发电的实际需求开展定转子双永磁激磁风力发电机系统的研究，包括：电机拓扑结构、电机电磁分析方法、电机多目标优化设计方法、电机数学模型、参数计算及最大发电功率跟踪控制策略等。最后进行50 kW样机试制，并在此基础上进行实验研究。在转矩密度方面，力争通过电磁优化设计使之达到100 kNm/m^3的水平。

风力发电是转变能源利用方式、解决能源危机和环境问题的重要手段。而风力发电大致可分为集中并网式和离网式风力发电。与集中并网式相比，离网式风力发电能够破解集中并网式风电产生波动大、入网难的困题，因此，离网式风力发电在很多特殊场合日益显出其重要性。众所周知，发电机是风力发电系统中最重要的能量转换装置，根据发电机型态可分为直驱和齿轮传动风力发电机两大类。与齿轮传动风力发电机相比，直驱风力发电机因摆脱传统机械齿轮箱带来的种种弊端受到了大家的青睐，然而过低的转矩密度是限制直驱风力发电机发展的一个重要因素。为此，本项目基于双向磁场调制效应，结合离网式直驱风力发电的实际需求，提出定转子双永磁激磁风力发电机，并展开对该电机进行系统全面的研究：总结出该种电机的结构特点；通过一维磁路法找出了该种电机槽极数匹配的规律；推导并验证了该种电机的反电动势和转矩方程；提出了另一种磁场增强型双永磁激磁电机；利用表面响应法优化了电机的结构参数提高了电机性能；设计并试制了一台小样机和一台100kNm级样机，实验测试了它们的性能。共发表论文10篇，其中SCI收录8篇；申请专利11项，其中6项授权；出版专著1部；培养毕业研究生3个；此外，“100kNm级电机技术”通过了成果鉴定。