异步电动机转子断条故障演化及相关因素分析

基于多回路理论,应用有限元方法建立了笼型异步电动机在转子有无断条故障情况下电磁场分析模型,从仿真计算与实验两方面对转子断条故障前后的定子起动电流波形、转子电流密度、转子各导条所受电磁力以及磁场分布进行分析研究,并总结出变化规律;同时对转子铁损进行了计算,应用探测线圈技术对气隙磁密的基波及三次谐波成分进行分析,从而提取电机转子断条故障的特征量.理论研究与实验结果的比较证实了该有限元模型的合理性,并且为异步电动机转子断条故障诊断和品质评估提供了理论基础和计算方法.

Faulty Evolution of Broken Bars in Induction Motors and Correlative Factors Analysis

The finite element models of a squirrel-cage induction motor in healthy and faulty case are developed based on the Multi-Loop Theory, and the healthy bars and the broken bars fault are studied from simulation and experiment. These studies are performed using the model to compute healthy and faulty cases performance data, which contain stator starting current waveforms, current density and magnetic force on the rotor bars, and the distribution of magnetic field for the case of no broken bars and fault. Meanwhile the iron core loss on rotor is computed, and the fundamental component and the third harmonic component of air gap flux density are analyzed by the search coil induced voltage detection technique. From these data, the faulty signatures are extracted. Theoretical approach together with experimental results confirms the validity of the proposed method, furthermore, this method which could help develop diagnostics of broken bars and performance evaluation of induction motor has great potential in future application.