自起动永磁同步电机起动过程退磁磁场的计算与分析  

Demagnetization Field Analysis and Calculation for Line-start Permanent Magnet Synchronous Motor During Start Process

作　　者：卢伟甫[1] 刘明基[1] 罗应立[1] 张健[1] 

机构地区：[1]华北电力大学电气与电子工程学院,北京市昌平区102206

出　　处：《中国电机工程学报》2011年第15期53-60,共8页Proceedings of the CSEE

基　　金：国家自然科学基金项目(50777018);"十一五"国家科技支撑计划项目(2008BAF34B02)~~

摘　　要：自起动永磁电机起动过程中的退磁磁场可能导致永磁体的不可逆退磁。为分析退磁磁场产生的原因,建立了计及饱和、涡流等多种因素影响的自起动永磁同步电机起动过程退磁磁场的时步有限元模型,并分项计算了永磁体作用、鼠笼异步电机效应及变频永磁发电机效应的影响。计算结果表明,重载起动时,从低速开始,永磁体内就出现波动变化的退磁磁场,并在接近同步速时退磁效应最明显;而空载起动时,退磁磁场仅波动一次,并在0.5倍同步速附近出现较强的退磁效应。由理论分析可知,在转速较低时,永磁体就存在退磁效应,其磁密呈波动变化的根本原因在于鼠笼异步电机效应与变频发电机效应的共同作用。算例计算结果验证了理论分析的正确性。最后通过实验验证了所提有限元计算方法的有效性。The demagnetization field during the starting process of line-start permanent magnet synchronous motors（LSPMSM） may cause the irreversible demagnetization of permanent magnet.For the further study of the causes of the demagnetization field,this paper established the time-stepping finite element models of LSPMSM considering the influence of saturation,eddy current and other factors.These models took account of the permanent magnet field,the squirrel-cage asynchronous motor effect and the variable-frequency permanent magnet generator effect comprehensively and separately.It was found that the demagnetization field in the permanent magnet alternates even at a low speed,and reaches the largest demagnetization point close to the synchronous speed during the start with heavy load.When the LSPMSM starts without load,a larger demagnetization field appears only once at around half the synchronous speed.The further analysis revealed that the appearance of the demagnetization field at low speed and its alternate variation are due to the squirrel-cage asynchronous motor effect and the variable-frequency permanent magnet generator effect.The results of the calculation example verify the theoretical analysis.Finally,the experiment validates the creditability of the calculation results of the above finite element method.

关 键 词：自起动永磁同步电机 退磁磁场 起动过程 时步有限元法 发电机效应 

分 类 号：TM351[电气工程—电机]