笼型转子断条感应电动机的易解数学模型

针对断条破坏了电机原有对称关系而使建模仿真变得困难,采用综合矢量法,建立了转子断条感应电动机易于求解的数学模型.对电机暂态及稳态仿真揭示了定子电流幅值与转矩随时间脉动的故障特征,得出了转子导条电流分布规律,表明与断条相邻及相距一对极距的导条电流最大.引人关注的是在转子端环间出现端电压,其值反映了转子电路不对称程度;揭示了故障特征随电机负载变化规律.定子电流实测与仿真结果相吻合证实了结论正确,有助于感应电机在线故障诊断.

Easy-solved mathematical model of squirrel cage induction motor with broken rotor bars

Broken rotor bars change the inherent symmetry of motor winding and bring the difficulty of modeling and simulation.The easy-solved mathematical model of the broken-rotor-bars squirrel-cage induction motor is established with synthetic vector for the question.Simulation on both the transient and the steady states of the motor reveals the fault features that both the amplitude of stator current and the electromagnetic torque are pulsed varying with time.The rotor bar current distribution is obtained,which shows that current has the highest value in the bars next to the broken one and away from one pair-pole's space.It is noteworthy that the voltage,which indicates the degree of asymmetry of rotor circuit,appears between two end-rings of the rotor.Meanwhile,the paper illustrates how the fault features change with the motor load.The simulation results are helpful for the on-line diagnosis,troubleshooting on the induction motor.The measured stator current is in accord with simulation result,thus confirming the conclusion's correctness.