What is the primary function of a frequency converter?

The primary function of a frequency converter is to change the frequency of an AC power supply to match the specific needs of the load. In many applications, particularly in industrial settings, the frequency of the power supply needs to be adjusted to ensure that motors and other equipment operate optimally. For example, equipment designed to run efficiently at a frequency of 60 Hz would need a frequency converter if supplied with 50 Hz power. This capability allows for improved performance and energy efficiency, ensuring that machines can operate at their designated specifications without damage.

The focus on frequency conversion is crucial in contexts such as variable speed drives for motors, where the speed is directly related to the frequency of the input power. By adjusting the frequency, the converter maintains precise control over the speed and torque of the motor.

In contrast, increasing voltage or reducing current flow are functions that relate to transformer or current-limiting devices, respectively. Converting AC to DC is specifically associated with rectifiers, which serve distinct purposes separate from frequency conversion. Thus, option B accurately identifies the core function of a frequency converter in the context of adapting AC power for various applications.