变频驱动引风机轴系扭振机电耦合建模与分析

Electromechanical Coupling Modeling and Analysis for Torsional Vibration of Shafting System of Variable Frequency Driven Induced Draft Fan

为了分析和解决引风机变频改造后遇到的扭转共振问题,利用Simulink/Simscape软件建立了变频驱动引风机轴系扭振的机电耦合模型。该模型可考虑三相变频器输入电压的谐波与相电压的不平衡、开关器件的死区效应与导通压降等影响传动轴所承受动态力矩的关键因素。通过算例揭示了在升速过程中,当风机转速超过某一临界转速后,扭转共振一直存在,这一现象与相关文献中的试验结果一致。

In order to analyze and solve the problem of torsional vibration after transform on variable frequency of induced draft fan, Simulink/Simscape software was used to establish an electromechanical coupling model for torsional vibration of the shafting system of variable frequency driven induced draft fan. This model considered factors influencing dynamic mo- ment on the transmission shaft such as harmonic of input voltage of the three-phase frequency converter, imbalance of phase voltage, dead-time effect of switching elements, forward voltage drop, and so on. Examples revealed that in raising speed process, when rotating speed of the draft fan exceeded critical speed, torsional vibration always existed, which was the same as described in relevant literatures.