Staff

Abstract:
Majority of industrial machinery and several mechanisms are driven by asynchronous motors. Such electro-mechanical systems are often affected by detrimental torsional vibrations, suppression of which is commonly performed by more or less effective passive, semi active and active dampers. In this paper there is proposed an alternative method of attenuation of torsional vibrations in such objects. Here, an asynchronous motor under the proper vector control can simultaneously operate as a source of drive and actuator. Using this approach, transient and steady-state torsional vibrations of the driven mechanical system can be effectively suppressed as well as its precise operational motion can be assured. The theoretical investigations are carried out by means of an advanced structural mechanical model of the drive system and circuit model of the asynchronous motor controlled using two methods: the direct torque control (DTC-SVM) and the rotational velocity controlled torque method (RVCT) originally developed in this paper. In the computational examples performed for three representative drive systems torsional vibration control ability is analyzed for various dynamic properties of the mechanical part and several parameters of the asynchronous motor control. From the obtained results it follows that for majority of tested parameters, transient torsional vibrations excited by step-wisely disturbed loadings of the driven object are successfully attenuated using both abovementioned vector control strategies. However, a suppression effectiveness of resonant steady-state torsional vibrations by means of these methods depends on the specific case of an asynchronous motor with a given electromagnetic stiffness in the stable operational range of its static characteristics.

Keywords:
active control, torsional vibrations, asynchronous motor, rotating systems, driving asynchronous motor, driving motor