What VFD properties matter the most to you? Medium voltage VFD is often a long term investment. The expected lifetime is typically at least 20 years. Thus, it is important to make the right choice when purchasing it. That is Read more…
Why do VFDs sometimes trip during grid faults? Grid disturbances and faults appear now and then. And it is desirable that the VFD does not trip every time such event occurs. Thus certain immunity against grid disturbances is desired. In Read more…
Types of harmonics How can we classify harmonics? What types of harmonics do we know? That is a subject of this short post. Different literature sources mention various classification. We just list here several categories based on our own practice. Read more…
Overdimensioning of VSDS – What are the consequences? How to dimension a variable speed drive system (VSDS) properly? Underdimensioning is a No Go but what about overdimensioning? Besides the initial investment cost, how does overdimensioning affect the technical side of Read more…
KYDS: Know Your Drive System KYDS -Know Your Drive System – is our new program where you learn more about variable speed drive system and the most important system components (transformer, VFD, electric motor, cooling system, harmonic filter). Scope of Read more…
How to take oil samples properly? In this short blog post we share a basic guideline and set of recommendations how to take oil samples properly. Introduction Analyzing the quality of transformer insulation oil by means of oil samples is Read more…
Success story on transformer rental for critically important compressor drive End of last year our company had the opportunity to rent the VFD transformer to support an important European production plant of a global chemical company. This case has proven Read more…
How to calculate the short circuit current in a correct way? Calculation of short circuit current is essential for the design, dimensioning and protection of electric systems. Such system may be for example a substation, a transmission line, a generator Read more…
InterCity-Express (ICE) – The German high-speed champion In this blog post we look at another high-speed champion on European railway tracks: the InterCity-Express, well known as ICE. These trains are the highest category trains in the fare system of Deutsche Read more…
Protection of VFD-fed motors How to properly protect an inverter-duty variable-speed electric motor? What protection is covered by the VFD? What shall be done externally? Which protection elements are most suitable? The article on protection of VFD-fed motors brings the Read more…