电压不平衡时异步电机内部磁密与电密分布特点及其对损耗影响  

Flux Density and Current Density Distribution Characteristics and Impact on Losses of Induction Motor under Unbalanced Voltage Conditions

作　　者：张元星[1] 赵海森[1] 刘晓芳[1] 王翔宇[1] 

机构地区：[1]华北电力大学电气与电子工程学院,北京102206

出　　处：《电机与控制应用》2014年第3期6-11,共6页Electric machines & control application

基　　金：国家863高技术基金项目(2009AA05Z207);中央高校基本科研业务费项目(12MS24)

摘　　要：异步电机在三相电压不平衡条件下运行,会导致损耗增加、运行效率降低。为研究该状态下电机系统节能新途径及不平衡抑制措施,以一台5.5 kW笼型异步电机为例,利用时步有限元法计算并分析了典型不平衡条件下定、转子铁心及转子导条不同位置磁密及电流密度随时间变化特点及其对损耗的影响。结果表明:电压不平衡时,定子绕组中较大的负序电流导致定子铜耗增加;转子导条中出现明显的偶次谐波电流,使得转子铜耗显著增加;电压不平衡度允许范围内,定、转子铁耗变化不大;与试验结果对比验证了分析结果的正确性。Unbalance voltage can lead to loss increase and efficiency decrease of the induction motor. In order to study the novel energy saving approaches and the suppression measures for unbalance voltage, taking a 5.5 kW squirrel-cage induction motor as an example, with time-stepping finite element method, the change characteristics of flux density and current density in different positions of stator and rotor cores as well as rotor bars were studied under typical conditions of voltage unbalance. And the effects of those changes on losses were also presented. The results show the increase of stator copper loss is caused by the larger negative sequence current in the stator windings in the condition of voltage unbalance, and the increase of rotor copper loss is significantly caused by the even harmonic current appearing in rotor bars obviously, the stator and rotor iron loss almost hasn＇t changed in the permissible range of voltage unbalance. The correctness of the analyzed results was verified by comparing with the experimental results.

关 键 词：电压不平衡 异步电机 磁密与电密 时步有限元 损耗 

分 类 号：TM343[电气工程—电机] TM936