Asynchronous and synchronous motor drives in comparison Medium voltage variable frequency drive (MV VFD) systems mostly utilize two types of electric motors: asynchronous and synchronous machine. This article compares some of the characteristics of both technologies. Aspects such as power Read more
What is a safety coupling? Safety coupling is a mechanical shaft component. It connects two pieces of the shaft. However, it has a special role: to protect the shaft line against excessive torque. That is why it is also referred Read more
Active magnetic bearings for high-speed motors This post presents some basic information about active magnetic bearing technology in modern variable speed drive systems. Two principal solutions for electrically driven turbomachinery Electric drives for turbomachinery can be realized in two ways: Read more
How well do you know variable frequency drives and drive systems? Take a short quiz to test your knowledge about variable frequency drives (VFD) and VFD based drive systems. 1. Nominal current of asynchronous motor with pf = 0.88 is Read more
How to size cables in high-power drive systems? Most common power connection in between drive system components is a cable. In this post we look at some factors to consider when sizing cables in high-power medium voltage variable frequency drive Read more
Operation of medium voltage drives: A service cost of ownership This post provides important considerations about the lifecycle cost of a medium voltage variable frequency drive (MV VFD) from the service perspective. The “end of life” and “life extension” options Read more
Are our blog posts generated by AI? So far we have published over 260 blog posts, most of them dedicated to variable frequency drives and drive systems. How do we create those articles? And are our blog posts generated by Read more
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