电压短时中断后电机的最大低电压穿越能力

Low Voltage Ride Through Capability of Induction Motor After Voltage Interruption

异步电机是工业生产中的重要设备,电压短时中断后,由于惯性电机会继续运行。根据稳态等效电路,建立了转差率与负载转矩、端电压间的一阶动态模型。利用该模型推导出电压短时中断后,转差率与临界时间的解析式。研究表明电压短时中断后,可以将电机看作为线性负载,其最大低电压穿越时间与负载转矩为反比例关系。该方法简单实用,可用来确定转动惯量等参数对电机最大低电压穿越能力的影响,Matlab下的仿真结果证明了其有效性。

Induction motor（IM）is important equipment among industries. After voltage interruption,IM will continue to operate because of inertia. The first-order dynamic model of slip,load torque and terminal voltage is set up based on IM steady-state equivalent circuit. And the universal analytic functions of slip and critical time are deduced from the model. It implies that,when voltage interruption occurs,IM can be regarded as linear load with its low voltage ride through（LVRT）time being inverse proportional to load-torque. This simple and practical analytical method can be used to ascertain the effect of inertia and other parameters on IM LVRT capability. Simulation result of Matlab proves its effectiveness.