Why is 400 Hz used as an aircraft power supply?

Answer 1

Although most all utility power in the world use either 50 Hz or 60 Hz, 400 Hz power systems are typically used in large aircraft. The reason for the higher frequency is that most of the power system parts, especially the 400 Hz alternator and 400 Hz motors are much smaller compared with similar 60 Hz equipment of the same power rating.

In aircraft, every pound saved in equipment weight, equates to about a five pound savings in gross weight during flight. When equipment weight is reduced, both airframe structure and fuel load can also be reduced.

As flux is inversely proportional to speed and speed is proportional to frequency

Higher the frequency lesser the flux required.Lesser the flux,lesser the core size.Lesser the size means less weight.Hence the pay load can be increased.

Also frequency above 400 hz not taken because the radiation takes place beyond this.

Answer 2

400 HZ power supplies are lighter and smaller than 60 HZ power supplies. Due to the amount of electrical consumption in an aircraft the lighter weight of the 400 HZ systems mean increased flight distance on the smae amount of fuel.

Answer 3

It is depending upon the rared design of manufacturer. it varies aircraft to aircraft.