The Basics Of Variable-Frequency Drives

Variable-frequency drives (VFDs) are electrical devices that allow a motor to run at any speed within its operating range. Vfd Drives is an integral part of most industrial machinery, such as conveyor belts and packaging machines. A variable-frequency drive has several components:

Variable-frequency types

There are three main types of variable-frequency drives: synchronous, asynchronous, and compound. 

As the names suggest, synchronous VFDs run at the same speed as the grid’s frequency; asynchronous VFDs run at a different frequency than their source; and compound VFDs combine both methods by adjusting their speed in response to changes in grid frequency.

Compound variable-frequency drives are most common because they’re more efficient than other types. They’re also easier to set up and connect to existing motors because they have fewer options for controlling motor current than synchronous or asynchronous models do.

Vfd Drives

Heat, power losses, and harmonics

When you’re buying a motor, one of the first things to consider is how much heat it will produce. This is especially important if you have sensitive electronics nearby. The higher the temperature, the more likely your equipment will fail when operated in close proximity to high-temperature motors.

Heat generation also means power losses—and those add up over time. If a motor is pulling too much current from an electrical system, that system may lose its ability to supply power at all as it gets overloaded by all those extra watts being pumped into inefficient circuits and devices. 

The result? Not only does this mean less energy efficiency for everyone involved (i.e., more wasted energy), but it can also lead directly back into overheating issues because there isn’t enough juice left over after paying off all those power bills!

Finally: harmonics! Harmonics are caused by interaction between different parts of any given circuit; they manifest themselves as unwanted noise—also known as radio frequency interference (RFI). 

When this interference reaches unsafe levels (as determined by local standards), even tiny amounts of electromagnetic radiation can cause serious damage over time or even start fires immediately upon contact with vulnerable materials like plastic or rubber

VFD benefits

Variable-frequency drives (VFDs) are a great way to cut energy costs, reduce maintenance costs, and increase motor life. Here’s how:

  • Reduced energy costs – Energy use is reduced because the frequency at which a motor operates can be varied as required. This means that motors only need to run at their optimum speed and power settings for specific operations.
  • Reduced maintenance costs – VFDs keep motors operating within their normal load limits, which prevents overheating and associated damage that can lead to high repair expenses.
  • Increased motor life – VFDs help prolong the useful life of motors by allowing them to operate efficiently in their normal speed range without overheating or overloading themselves during heavy-duty operation, thereby reducing downtime and maintenance costs associated with premature failure.


This article has been a quick introduction to variable-frequency drives (VFDs). If you’re not familiar with them, we hope that it gave you a better understanding of what they do and why they’re so important in today’s industrial world. 

Vfd Drives can be used in all sorts of applications–from simple conveyor belts or fans all the way up to large-scale manufacturing plants–and they have wide-reaching benefits for both companies and consumers alike.