摘要
该文开展大型永磁直驱发电机磁固耦合特性研究。采用共形映射方法,计算考虑齿槽效应的气隙磁场标量磁势;基于离散电流元和磁等效电路模型,定量模拟发电机定转子局部的磁饱和效应,通过数值迭代得到气隙磁场强度分布;引入一系列均布的磁等效弹簧,模拟定转子之间的耦合作用,建立永磁直驱发电机磁固耦合有限元分析模型。以实际在役兆瓦级永磁直驱发电机为对象,通过电磁有限元计算结果验证所提出的气隙磁场强度分析方法;基于金风兆瓦级永磁发电机测试平台,开展转/定子耦合系统模态测试,与理论模型得到的固有频率和模态振型进行对比。在此基础上,分析气隙长度和转子转速对耦合系统固有频率的影响。研究结果对于准确评估发电机振动能量、规避危险共振点指导机组设计等均具有重要的参考价值。
The magnetic-structural coupling characteristics of large permanent magnet direct drive generator are studied in this paper.Using the conformal mapping method,the scalar magnetic potential of air gap magnetic field considering cogging effect is calculated.Based on the discrete current element and magnetic equivalent circuit model,the local magnetic saturation effect of generator stator and rotor is quantitatively simulated,and the air gap magnetic field intensity distribution is obtained by numerical iteration.A series of uniformly distributed magnetic equivalent springs are introduced to simulate the coupling between the stator and rotor,and the magnetic-structural coupling finite element analysis model of the permanent magnet direct drive generator is established.Taking the megawatt permanent magnet direct drive generator in service as the object,the proposed air gap magnetic field analysis method is verified by the electromagnetic finite element calculation results.Based on the test platform of Goldwind megawatt permanent magnet generators,the modal test of rotor/stator coupling system is carried out and compared with the natural frequencies and modal shapes obtained from the theoretical model.On this basis,the effects of air gap length and rotor speed on the natural frequencies of the coupling system are analyzed.The results can provide important reference for accurate evaluation of generator vibration energy,avoiding dangerous resonance points and guiding unit design.
作者
张志弘
韩勤锴
徐学平
颜益峰
彭超
褚福磊
ZHANG Zhihong;HAN Qinkai;XU Xueping;YAN Yifeng;PENG Chao;CHU Fulei(Xinjiang Goldwind Science Technology Co.,Ltd.,Xinjiang Uygur Autonomous Region,Urumqi 830026,China;Department of Mechanical Engineering,Tsinghua University,Haidian District,Beijing 100084,China;Research Institute of Frontier Science and Technology Innovation,Beijing University of Aeronautics and Astronautics,Haidian District,Beijing 100191,China)
出处
《中国电机工程学报》
EI
CSCD
北大核心
2023年第8期3217-3226,共10页
Proceedings of the CSEE
基金
国家自然科学基金项目(11872222)。
关键词
永磁直驱发电机
磁固耦合
模态分析
共形映射
磁等效弹簧
permanent magnet direct drive generator
magnetic-structural coupling
modal analysis
conformal mapping method
magnetic equivalent springs
