变频谐波诱发轧机传动非线性耦合振动研究

Investigation into Induction of Nonlinear Coupling Vibration of Main Drive System of Rolling Mill by Harmonics of Variable Frequency

利用扭矩遥测系统在线监测轧机传动轴上扭振信号时,信号特征显示轧机发生机电耦合振动.为研究其机理,利用Matlab/Simulink仿真获得了变频器输出电流基波与谐波分量以及由此产生的电机输出谐波力矩,利用ANSYS分析了轧机传动机械系统的固有特性,建立了含非线性刚度、阻尼项的传动机械系统等效动力学模型,揭示了谐波激励与轧机结构耦合机制及特征.仿真计算表明:减小谐波源幅值和增加阻尼均可大幅降低振动能量.

When the torsional vibration of the drive shaft of rolling mill is monitored on-line by means of the torque telemetry system , the signal features show that the electromechanical coupling vibration occurs in the main drive system.In order to reveal its mechanism , the harmonic components with fundamental wave in the cycloconverter output current and the corresponding harmonic torque are obtained by a Matlab /Simulink simulation , the characteris-tics of drive mechanical structure are analyzed by means of ANSYS .Then, an equivalent kinetic model of drive me-chanical structure with nonlinear stiffness and damping term is built , and the coupling mechanism and characteristic of harmonic excitation and mill structure are revealed .Simulation results indicate that both reducing harmonic amplitude and increasing damping can decrease vibration energy to a large extent .