AC Drives

A variable frequency drive (VFD) likewise named adjustable frequency drive, variable speed drive, AC drive, inverter drive, or just inverter, is a specialized motor controller based on power electronics that varies frequency and voltage. GE and BBC (ABB) originally developed the first patents in 1910 and 1911, but the modern version we see today did not surface until the 1980s.  

Currently VFDs can be found just about anywhere that electric motors are required, by the application, to have the capability of speed adjustment. The applications range from simple appliances to critical plant sized fans at nuclear facilities. One of the greatest benefits of using VFDs in applications is the improved energy efficiency as well as the beneficial effects of power factor correction. Roughly 25% of the world’s energy is consumed by electrical motors where the usage of VFDs is still minimal.

Since the 1980s, improved power electronics in the form of power density, size, and performance have reduced overall cost and physical size of VFDs. These major technology shifts have made VFDs more available to users on a greater scale and grow every year.

Industrial Control Direct, is one of the few distributors in the US that has a staff of a dozen engineers and specialists that design, engineer, build, and support VFDs on a grand scale. We have over 250 years of collective experience in applications. The staff is called the Applications Engineering Group (AEG) and further information can be found here:

If you do not see a drive that fits your application, please email us at or give us a call.