How does a variable frequency drive (VFD) affect an electric motor?

A variable frequency drive (VFD) primarily affects an electric motor by controlling its speed through frequency variation. Electric motors typically operate at a speed that is directly proportional to the frequency of the electrical supply. By adjusting the frequency of the power supplied to the motor, the VFD enables precise control over the motor's operational speed and torque.

Increasing the frequency results in a higher speed, while decreasing it lowers the speed. This capability allows for enhanced energy efficiency since motors can run at speeds that match the actual requirements of the application, thus reducing energy waste associated with running at a constant high speed. Additionally, this control can also lead to smoother acceleration and deceleration, minimizing mechanical stress on motor components.

The other options focus on different aspects of motor operation. While a VFD indirectly contributes to energy savings and can help prevent electrical issues through improved control, its primary function is the dynamic adjustment of the motor speed via the manipulation of frequency.