单相Smith电动机瞬态分析

Transient-State Analysis of Single Phase Smith Induction Motors

对三相感应电动机Smith接法单相运行时的瞬态过程进行仿真分析。为了得到瞬态特性,推导出电动机定子绕组端电压约束条件,建立起单相Smith电动机在αβ坐标系下的瞬态数学模型。编写计算机仿真程序,通过实例对三相感应电动机Smith接法单相运行时的瞬态过程进行仿真计算,计算结果与试验结果基本吻合,验证了该模型的正确性;用对称分量法分析三相感应电动机Smith接法时的电路系统,确定电容的数值。对仿真结果进行分析,单相Smith电动机在负载一定、转速一定的情况下通过选择恰当的电容可以实现完全平衡对称运行。单相Smith电动机在由三相电机额定相电压的单相电源供电时带负载能力较弱,起动转矩较小,适合于对起动要求不高的风机泵类负载,当要求起动转矩较大时,可采用双值电容来实现。

This paper presents a transient-state analysis of single-phase operation of a three-phase induction motor with the Smith connection. To obtain the property of transient state, such as the phase voltages, phase currents, and torque, according to the dynamic mathematical model of three-phase induction machine in αβ and boundary equation of three-phase induction motors with the Smith connection, the computer emulation program is compiled. The program is applied to emulate transient process of single-phase operation of three-phase induction motors with the Smith connection through example. Experimental data demonstrates accuracy of this model. Symmetrical components method is employed in the analysis of the asymmetrical system of the Smith connection, the value of the capacitance is determined. Emulating results are also studied here.