Speed and position encoders in variable speed drive systems Abstract Modern variable frequency drives often operate in speed-encoderless mode. It means that there is no physical sensor to measure the rotational speed of the motor. Although the encoderless operation is Read more
How to interpret dual rating transformers? You might have seen transformer data with two different values of apparent power, such as e.g. 20/25 MVA or 75/100 MVA. What does it mean and how to deal with dual rating transformers? Transformer Read more
What has a transformer and a gear in common? Transformer and gearbox are two quite different devices. Nevertheless, they have something in common. The analogy described in this article may help to understand how a drive system is dimensioned and Read more
What is the relationship between VFD input and output current? Introduction Variable frequency drive (VFD) is often seen as a black box. This black box converts fix voltage and frequency supplied from the grid into variable voltage and variable frequency Read more
Different types of drive redundancy and their use cases Redundancy in medium voltage (MV) drives is a critical design consideration aimed at enhancing the reliability and availability of motor-driven systems. Drives with some types of redundancy are used in applications Read more
On-demand webinars: Final sale (last 24 hours) MB Drive Services is providing webinars on drive related topics since more than 3 years. Initially, those webinars were live through zoom. Since May 2024 we have been using the WebinarJam platform to Read more
Multi-motor drives and their coupling Multi-motor drives in this context represent applications where multiple motors work together to drive specific load system. Unlike individual drives, there is certain coupling between the motors. Hard and soft coupling The motors can be Read more
Why torsional vibration in variable speed drive systems deserves an attention? Introduction I am an electrical engineer, same as probably most of the readers of our blog. The electro-mechanical interaction within the drive system is therefore not so easy to Read more
Neutral point treatment of a converter transformer A common question of system integrators or end users is about the neutral point treatment of a converter transformer. Can or shall the neutral point be earthed? What are the consequences for the Read more
VFD protection reaction Reliable protection is key for long term successful operation of a variable frequency drive (VFD). There is a wide range of situations outside of the normal operation to what the drive system shall respond. In this blog Read more