John in CR said:
Miles, I was looking at your motor's phase resistance. Is that correct? If so, are you sure you're not skimping too much on the copper to obtain such low iron losses. It seems like the end result will be extremely high efficiency at cruise with very low cogging, so you'll barely feel the motor if pedaling unpowered and regen braking can be part of the equation, which are great criteria. The compromise is increased losses during acceleration or the sustained loads of hills or strong headwinds, when higher current is required.
Hi John,
The phase resistance can only be interpreted in the context of the torque constant..... Of course it's only a simulation but note that my design has the highest specific Km of all the motors on the chart, so far. Which is precisely what I was aiming for
I did quite a lot of experimentation varying the loading of the electrical circuit against that of the magnetic circuit and I think I'm pretty much where I want to be with that.
Running it at 2400 rpm, which is the intended speed for this iteration, the efficiency is 94% for 1355 Watts output and the peak efficiency is 95.4% for 680 Watts output.
If I wanted to run it at 6000 rpm, the iron losses would still be manageable.