异步电机V/f控制系统轻载稳定性仿真研究

Light Load Stability Simulation of IM V/f Drive System

异步电机开环V/f控制系统在空载或轻载时存在持续振荡的不稳定问题。该类系统的轻载稳定性是一个非常复杂的问题,与定子电阻、转子惯量、死区时间、DC滤波电容、载波频率、系统谐振频率等很多因素有关。目前,有关抑制振荡方法的研究很多,但对振荡起因的研究却相对较少。该文主要对异步电机V/f控制系统轻载持续振荡的起因进行研究。首先,通过仿真建模详细分析了系统出现持续振荡时的不稳定现象。然后,通过理论推导,从传统控制理论的角度对系统轻载振荡的原因进行了研究,并分析了系统中各参数对此振荡的影响。推导出的结论与实际情况吻合,根据该文的分析结果可对异步电机V/f开环控制系统的振荡情况进行预测。

Induction motor V/f open-loop drive system suffer sustained oscillation problem in light load condition. Many methods have been presented to suppress the oscillation. However, a generally accepted theory about the cause of this oscillation problem is not revealed. This paper mainly focuses on the research of the cause of the sustained oscillation problem of IM V/f drive system. Through simulation modeling, the system instability is analyzed in detail based on the simulation results. Then by theoretical derivation, the reasons that result in the instability under light load condition are studied, and the influences on system stability of various parameters are also analyzed. The conclusions derived in this article are consistent with the actual phenomenon very well. In addition, the derived conclusions can be used to predict the oscillation of the IM V/F open-loop control system.