The definition of a VFD speed control, or variable frequency drive, is a device used to regulate the speed of an electric motor by changing the frequency of the power supplied to it. This technology is used in many applications such as elevators, conveyor systems, pumps, and other machinery. A VFD works by varying the amount of voltage supplied to the motor. The higher the voltage, the higher the speed of the motor. The lower the voltage, the lower the speed. VFDs are very efficient in controlling speed, torque, and power consumption of motors. They also help reduce electrical noise and harmonics. In addition, they offer better control of energy consumption and improved motor life. VFDs are commonly used in industrial applications, as they are able to provide precise control over the speeds and torque of the motor. They are also used in HVAC systems to ensure that the system runs at the optimum speed and with the least amount of energy consumption.