三相异步电动机空载时定子阻抗不对称故障模型

摘要

为研究三相异步电动机定子绕组不对称故障对电机运行特性的影响,分别定义可表征定子绕组电阻和电感不对称故障程度的电阻不对称率和电感不对称率两个参数,并应用多回路理论建立描述电机定子阻抗不对称故障特性的微分方程.通过稳态时方程两边各项系数相等的原则,将电机微分方程组转化为线性方程组,解方程可得到定转子电流及电磁转矩关于阻抗不对称率的模型.最后,以鼠笼式异步电动机为例,分析电阻不对称率和电感不对称率对电机运行特性的影响,并用仿真和实验结果验证所得结论的正确性.%In order to study the impact of the three-phase asynchronous motor stator winding asymmetry faults on the motor's operating characteristic,two parameters,the resistance asymmetry rate and the inductance asymmetry rate,were defined to characterize the degree of the stator winding impedance asymmetry fault.Based on this definition,the differential equations were established to describe the features of the stator impedance asymmetry faults through the multi-loop theory.With the principle that the two sides of the equation balance at steady state,the differential equations can be translated into a set of linear equations,which can be solved to obtain the models of stator and rotor current and electromagnetic torque on the impedance asymmetry rate.Finally the squirrel-cage induction motor is taken as an example to analyze the impact of the resistance and the inductance asymmetry rate on the motor's operating characteristics.Simulation and the experimental results verify the correctness of the conclusion.