The use of variable frequency drives (VFDs) in commercial and industrial facilities is growing, and for good reason. VFDs can reduce motor electricity usage by 25 to 85 percent, depending on the application. VFDs also minimize wear and tear on motors, reducing maintenance costs and increasing equipment life.
Despite all of these benefits, there are some issues to consider when installing VFDs. One of these is the potential for harmonics issues.
In some cases, VFDs cause harmonic distortion in a motor's electric currents, which can result in excessive heating. A number of solutions are available to reduce harmonic distortion, including active and passive harmonic filters, 18-pulse harmonic-reduction drives and active front-end drives. A harmonics analysis of the system can help in selecting the right solution.