VFD testing: Introduction Abstract This new series on VFD testing will guide you through various aspects of testing of variable frequency drives (VFD) and drive systems. We will discuss tests required by standards (particularly IEC), factory acceptance tests, site acceptance tests and system tests, such as full load combined test Read more
Dealing with critical speeds This post explains some basic considerations related to variable speed motors and their critical speeds. The fact that motor operates at variable speed makes it more challenging from rotordynamic perspective in order to avoid critical speeds within the operation speed range. At the same time, VFDs Read more
VFD multidrives and investment cost Continuing our popular series on benefits of multidrives [1] we will talk about multidrive investment cost, especially when comparing it with alternative based on single drives. Introduction VFD multidrive solution offers plenty of benefits. Several of them had been discussed and explained in our previous Read more
VFD multidrives: Grid harmonic performance This is the continuation of our short series on benefits of VFD multidrives [1]. We have already explained improved energy efficiency [2] and reduced footprint [3]. Today’s article focuses on grid harmonic performance and how a multidrive solution has the edge over individual single drives. Read more
VFD multidrives: When footprint matters Reduced footprint as additional benefit of VFD multidrives VFD multidrive solution can, among other benefits (see [1]), substantially reduce the total space required for the installation. In this article we will explore the ways how multidrives reduce footprint providing the users with another competitive edge. Read more
Power, speed and torque The purpose of variable speed drive systems is basically the ability to provide required torque at corresponding speed. In simple words: to turn the shaft. Of course, the quantities of power, speed and torque are coupled together. This article is a bit more theoretical review. However, Read more