tilopa
Well-Known Member
There is a relatively new electric motor that claims some pretty impressive power density, 10kw/kg (6hp/lbs), and torque density of 30Nm/kg: YASA-400 | YASA Motors
Max Peak Power = 150kw (202hp) @ 700v
Peak Torque = 400Nm
Continuous Power = 90kw (120hp)
Peak Efficiency = 95%
Speed Range = up to 7500rpm
Weight = 22kg (48lbs)
Size = 280mm x 75mm
The power graph can be seen in the PDF at the bottom of the website, and it has some pretty interesting characteristics. At 3600 rpm peak torque can be achieved, although with lesser efficiency, and at the same rpm with lesser torque 90% efficiency is obtained. So, at takeoff high torque and power can be used for a short period of time, and at cruise altitude torque and power is reduced and higher efficiency maintained.
Now, I know 3600 rpm is not ideal, but for cruise it may be. But the fascinating thing about these electric motors is the flexibility relative to the torque curve. So, with this motor you could fit a prop for 3600 rpm and high torque angled blades (cruise prop), so at takeoff you ramp up power by increasing torque for a short period (400Nm is pretty impressive torque for 3600 rpm), and as air moves over the prop and the torque requirements decrease you move into higher efficiency and continuous power. You just can't build that kind of torque flexibility into an ICE. So, you can have good takeoff performance and even better cruise performance. Am I missing something? I'm sure you engineers are gonna tell me.
700 volts is pretty scary, I'd be surprised if there is a battery that can safely handle the high discharge rate needed to meet that power. But apparently they have already tested another motor they have, the Yasa-750, with a battery pack in an electric race car. Actually that motor might be better suited for airplane use. It has max torque of 750Nm @ 1300 rpm (too low rpm), but at its max rpm of 2000 it has about 480Nm of torque, and a max continuous power of 55kw (73hp) at 25kg.
Are these available off the shelf and cheap? Probably not, the 750 can be purchased, I'll find out the price. But the 400 if probably not available for the individual buyer yet.
Max Peak Power = 150kw (202hp) @ 700v
Peak Torque = 400Nm
Continuous Power = 90kw (120hp)
Peak Efficiency = 95%
Speed Range = up to 7500rpm
Weight = 22kg (48lbs)
Size = 280mm x 75mm
The power graph can be seen in the PDF at the bottom of the website, and it has some pretty interesting characteristics. At 3600 rpm peak torque can be achieved, although with lesser efficiency, and at the same rpm with lesser torque 90% efficiency is obtained. So, at takeoff high torque and power can be used for a short period of time, and at cruise altitude torque and power is reduced and higher efficiency maintained.
Now, I know 3600 rpm is not ideal, but for cruise it may be. But the fascinating thing about these electric motors is the flexibility relative to the torque curve. So, with this motor you could fit a prop for 3600 rpm and high torque angled blades (cruise prop), so at takeoff you ramp up power by increasing torque for a short period (400Nm is pretty impressive torque for 3600 rpm), and as air moves over the prop and the torque requirements decrease you move into higher efficiency and continuous power. You just can't build that kind of torque flexibility into an ICE. So, you can have good takeoff performance and even better cruise performance. Am I missing something? I'm sure you engineers are gonna tell me.
700 volts is pretty scary, I'd be surprised if there is a battery that can safely handle the high discharge rate needed to meet that power. But apparently they have already tested another motor they have, the Yasa-750, with a battery pack in an electric race car. Actually that motor might be better suited for airplane use. It has max torque of 750Nm @ 1300 rpm (too low rpm), but at its max rpm of 2000 it has about 480Nm of torque, and a max continuous power of 55kw (73hp) at 25kg.
Are these available off the shelf and cheap? Probably not, the 750 can be purchased, I'll find out the price. But the 400 if probably not available for the individual buyer yet.
