Torsional interaction and mitigation in variable speed drive systems: What is the root cause? Why bother about torsional vibration? How to do a proper electric-mechanical integration? How to minimize or mitigate torsional vibration and get peace of mind? What is the role of VFD control in the whole story?
Torque meter in variable speed drive systems Unlike electrical quantities the measurement of torque is not an easy task. Hence in most cases the torque is not measured directly but calculated (estimated) from electrical signals. But what if you need high absolute accuracy of torque control? In such case a Read more…
Cell bypass – What you should know Today we will discuss the cell bypass in cell-based medium voltage variable frequency drives (MV VFD). What is the purpose of such bypass? How is it technically implemented? What happens when the bypass is activated? And finally, how does cell bypass impact the Read more…
One reason for torsional vibration issue:Torque ripple In this post we look at torque ripple, its background, character and impact on the shaft string. After reading through you will have a brief idea what the torque ripple is and how to deal with it in a variable speed drive system. Read more…
Electro-mechanical interaction:Growing trend of vibration issues We have observed numerous vibration issues associated with rotordynamics in variable frequency drive systems across the industries. The trend is growing and this shall be a warning sign. There are multiple reasons for this trend. Here we name the most important ones from our Read more…
Electro-mechanical interaction:Introduction Electric variable frequency drives provide lot of benefits in terms of energy savings, controllability and flexibility. But the VFD is just means to control the speed or torque of electric motors. The useful work is provided by the driven load such as e.g. pump, fan, compressor or mill. Read more…