What is the primary function of the 400 Hz frequency changers?

The primary function of 400 Hz frequency changers is to supply power, particularly in specialized applications such as aviation and certain industrial settings. Most electrical equipment in these environments is designed to operate at a higher frequency, which allows for smaller transformers, motors, and other components due to reduced size and weight. This is particularly beneficial in aviation, where weight is a crucial consideration.

These frequency changers take standard electricity (typically at 50 or 60 Hz) and convert it to 400 Hz, enabling efficient power distribution for aircraft systems and other equipment that require this frequency. In addition to providing power, operating at this higher frequency can improve the performance of electrical systems, making them more efficient in specific scenarios.

The other options do not pertain to the primary function of frequency changers. For instance, converting AC to DC is typically a function of rectifiers, while cooling and synchronization are generally performed by different devices and systems in electrical engineering.