A variable frequency drive (VFD) controls the speed of a three-phase AC motor by adjusting the frequency and voltage of the electrical power supplied to the motor. This technology offers precise motor control, allowing for smooth acceleration and deceleration. For example, in industrial settings, these devices can regulate the flow of liquids through pipes by controlling pump motors.
The ability to precisely control motor speed results in significant energy savings, reduced mechanical wear on equipment, and improved process control. Historically, controlling motor speed involved inefficient methods like mechanical throttling or rheostats, which wasted energy and generated excess heat. Variable frequency drives provide a modern, efficient alternative, optimizing industrial processes and reducing operational costs. Their development and refinement have been crucial for advancements in automation and energy efficiency across various industries.