In the AFD operating frequency range, what is the output frequency range identified from B to C associated with?

The output frequency range identified from B to C in the AFD operating frequency range is associated with constant output voltage while frequency varies. In this context, an adjustable frequency drive (AFD) is designed to control the speed and torque of electric motors. As the frequency output of the AFD changes, particularly in the range from B to C, the drive maintains a constant voltage level while allowing the frequency to vary.

This is crucial for applications requiring specific motor performance characteristics. By keeping the voltage constant while allowing frequency adjustments, the AFD ensures that the motor operates efficiently at different speeds. This is especially important to avoid excessive motor heating and to maintain an optimal magnetic field for the motor's performance.

In this scenario, while the motor frequency can change to adjust speed, the drive compensates by keeping the voltage stable, which helps in achieving a desired torque and smooth operation. Such a method is integral in providing the necessary power characteristics for the motor throughout its operating range.