Astro Flight motor comparison

[Sharkboat]

Astro Flight motors have been shown to work well on e-bike applications. They have a high resistance to heat and are up to 93% efficient. However, this is only the peak efficiency and is usually achieved at about half of the low end of the typical power range. For the 3220, this is 2000 Watts. At very low power, the efficiency drops off rapidly. Running a very high voltage/ high rpm is one way to increase the range of power that the motor can run above 90% efficiency.
My goal is to have an ebike that runs at above 90% motor efficiency for most or all of the time. This will allow the motor to not overheat, increase the life of the motor and motor controller, have a longer range, and use less batteries.
The 3220 is twice as powerful as the 3210. The other option is the custom Matt Shumaker 3230 motor, which is 50% more powerful than the 3220. This motor would achieve peak efficiency around 3000 Watts.
http://endless-sphere.com/forums/viewtopic.php?f=28&t=18681
The 3230 would have the same power as a 3210 and 3220 combined. My theory is that using a 3210 and 3220 combined would be more efficient than the 3230 alone.
The gear ratios and many other factors complicate this question.
Does anyone have additional information about improving the efficiency of an electric drive system, or know where I could find the information online?

 

[Miles]

I guess the first question is how wide a power range you need?

This spreadsheet might help:
http://www.endless-sphere.com/forums/viewtopic.php?p=312555#p312555

 

[FFR Trikes]

Shark,

Running a single Astro will almost always be more efficient than twins. This is mainly due to losses from an extra controller, extra motor, and losses through the extra synchro belt.

We've been working with Matt over the last couple years and we've found that a kV between 110-180 offers max efficiency with those motors. Also, the Wye wound motors have improved efficiency over Delta and maximize controller life.

The 3210 series motors are a good option for efficient setups that want a bit of pep. The 8T is our motor of choice in that series. It's over 90% efficient to 47A, (2000W @ 44.4V).

The 3215 is our favorite all around motor, it's over 90% efficient to 63A, (2800W @ 44.4V).

Of the 3220 series, the 4 turn is our pick. It's over 90% efficient to 94A, (4100W @ 44.4V).

The 3220 will be least efficient at lower power levels, while the 3210 will be most efficient at lower power levels, the 3215 is a nice blend of the two.

The key to keeping these motors at their optimum output is by limiting current, we do it with the LRC-CA that we worked with Grin Tech (Justin @ Ebikes.ca) to develop: http://www.ffrtrikes.com/Cycle-Analyst-for-RC-applications-p/ca-lrc.htm

Alternatively, gearing dictates how hot these motors will run, and we've found it to be 30mph max for the 3210, 35mph for the 3215, and 40mph for the 3220. These are based on the aero profiles of a recumbent tadpole trike.

Hope all this helps.

-Tommy

 

[Sharkboat]

Thanks for your help. I discovered your website a few years ago and love your products.

 

[FFR Trikes]

Very cool! Glad we could help.

-Tommy

 

[carlodegz]

can I ask what gearing did you use to let this motor run at their maximum?