Retrofits of DOL motors: Low-hanging fruit? Despite clear benefits of VFDs in motor drives, most industrial motors are still of fix-speed type. This is true for newly manufactured motors and even more for the installed base. Hence there is a Read more
Bypass in VFD applications Have you also come across that question: ‘What is actually meant with VFD bypass?’ This article presents 3 different meanings of bypass in VFD applications. Confusion about meaning of bypass I have noticed a common misunderstanding Read more
Tram CKD Tatra KT8D5 In this post we introduce a legendary tram KT8D5 made by famous Czechoslovak company CKD (Ceskomoravska Kolben-Danek). The tram CKD KT8D5 is a work horse that provides efficient and reliable public transport in many cities in Read more
Braking capability of VFD fed motors Not every VFD is capable of active braking. And not every application requires active braking either. In today’s post we are going to review the braking capability of most common medium voltage VFDs. Let’s Read more
What does purely inductive network actually mean? When calculating network harmonic distortion of variable frequency drives (VFD) there are basically two ways differentiating in complexity and eventually also accuracy. One is a simple harmonic calculation while the other option is Read more
How to diagnose bearing issues Bearings are key mechanical components of rotating machines and motors are obviously no exception. Bearing failures make a considerable portion of overall motor failures. In this post we look at factors influencing bearing lifetime, explore Read more
VFD Industry Requirements: Mining and Minerals In this post we will explore VFDs working in the mining and minerals market segment. What are the services, drive requirements and technical challenges? Let’s have a brief look. Drives in the mining industry Read more
What makes electric drives superior? We are very passionate about VFDs and electric drives in general. They have some unique features that make them outstanding compared to other types of drivers. What are some of these properties? This post lists Read more
Pendolino (680 series Czech Railways) This article presents the high-speed train “Pendolino” of 680 series operated by the Czech Railways. In Czech republic the tilting express train consists of seven carriages. Czech Railways operate them as SuperCity (SC) category. All Read more
VFD versus gas turbine In this post we are going to compare two variable speed drive solutions: an electric drive consisting of a VFD and a motor and a gas turbine. Gas turbine is an internal combustion engine, i.e. an Read more