Back to basics: VFDs and harmonic mitigation

摘要

From the time of their entry in the field of electric motor control in the early 1950s, variable frequency drives (VFDs) have continually evolved and been improved upon at a rapid rate. There are two primary reasons for this frenzied growth and refinement. The first is that adding variable-speed operation to most industrial apparatuses, such as pumps, fans, blowers, cranes, hoists, elevators, etc., results in considerable energy savings. The second is that VFDs offer the most efficient method of controlling the speed of ac motors.