Explaining WHY 400hz power weighs less would have been useful. The article is a one-paragraph "because" with a lot of padding.
Power doesn't come from nowhere. It's taken as some form of output from the gas turbines driving the turboprop. There are several ways this COULD be done, bearing in mind that these things rotate at 2,000 to 20,000 RPM depending on where you are between the fan and the actual turbine jet engine part. It's done as a shaft drive through a gearbox as I understand it, which implies mechanical parts, wear and cost.
I have no idea if the step down from 2k to 50hz is painful but I can see from the web 400hz is closer to the same functional RPM of the engine parts as-is so it may be this simplies the gearbox considerably: less gear stages == less loss over the gearing.
The other aspect is that the electrical parts of the power system are lighter at the higher frequency too. A 400hz transformer is meaningfully smaller and lighter than a 50hz one.
This is the same idea as switching power supplies but planes had to solve that before power semiconductors were cheap enough.
The power frequency also has an impact on the size of all the induction motors.
I guess if you were designing it from scratch today you would let the generator produce power at whatever frequency the mechanical engineers tell you they want to and the power electronics could convert it without problems. You would do the same thing the other way around on the motors.
The article is stupidly wrong. You don't need less generators or alternator with higher frequencies.
Instead, for each generator you have, you need less copper winding, less iron mass, making generators smallers.
Also, transformers get smaller for the same reason, and thus, lighter.
Explaining WHY 400hz power weighs less would have been useful. The article is a one-paragraph "because" with a lot of padding.
Power doesn't come from nowhere. It's taken as some form of output from the gas turbines driving the turboprop. There are several ways this COULD be done, bearing in mind that these things rotate at 2,000 to 20,000 RPM depending on where you are between the fan and the actual turbine jet engine part. It's done as a shaft drive through a gearbox as I understand it, which implies mechanical parts, wear and cost.
I have no idea if the step down from 2k to 50hz is painful but I can see from the web 400hz is closer to the same functional RPM of the engine parts as-is so it may be this simplies the gearbox considerably: less gear stages == less loss over the gearing.
The other aspect is that the electrical parts of the power system are lighter at the higher frequency too. A 400hz transformer is meaningfully smaller and lighter than a 50hz one.
This is the same idea as switching power supplies but planes had to solve that before power semiconductors were cheap enough.
The power frequency also has an impact on the size of all the induction motors.
I guess if you were designing it from scratch today you would let the generator produce power at whatever frequency the mechanical engineers tell you they want to and the power electronics could convert it without problems. You would do the same thing the other way around on the motors.
The article is stupidly wrong. You don't need less generators or alternator with higher frequencies. Instead, for each generator you have, you need less copper winding, less iron mass, making generators smallers. Also, transformers get smaller for the same reason, and thus, lighter.