podolefsky

13 May 2011, 1321

For a while I've been trying to put together a way to compare across some common motors. I think I've figure out a way to plot all this data that might actually be useful.

I'm doing this because there don't seem to be any standards, which makes it almost impossible to compare data from different manufacturers. I've tried to compile the best data I could find. As much as possible, these graphs are based on real dyno data (or what appears to be real dyno data). In some cases I've made assumptions to fill in gaps in the available data, e.g. assuming torque is directly proportional to current. It might not be perfect, since this data is all kind of sketchy.

Therefore: I am not responsible if you get one of these motors and find out it doesn't perform as expected. There are a million reasons this could happen, including bad data (don't blame the messenger!), bottlenecks in your system (such as weak batteries), etc. Just sayin'.

The graphs below show kW, motor torque, and adjusted wheel torque at 72V and 5:1 gearing on the left. On the right I adjusted the gearing so that all motors made 300 ft-lb at the wheel, and listed the gearing required.

Notes:

-Motors are running at different currents. I'm using the current limits that I could find from manufacturers. I think this is fair. If an AC-20 can handle 550A and the ME0709 can only handle 300, that's how they should be compared.

-The ME1003 is treated like an ME0709 with a 500A current limit (67% increase in torque, all else the same).

-I used the max efficiency listed. I did not adjust for changes to efficiency with RPM or current.

-The Dual Agni is assuming a parallel configuration. It looks impressive, but keep in mind it needs 800A to achieve this performance. Plot made by doubling torque.

-AC-20 96V plot was made by extending torque knee to 33% higher RPM.

Please let me know if you see anything glaringly wrong with this data. I'll keep trying to fix it up and get it as accurate as possible.

PDF (http://www.colorado.edu/physics/EducationIssues/podolefsky/EV_project/all_motors.pdf) of the graphs below.

http://www.colorado.edu/physics/EducationIssues/podolefsky/EV_project/all_motors.png

Plots below are for rated continuous current (under construction) and geared for 70 mph top speed.

- Note that the AC-20 is RPM limited to 70 mph at 8000 RPM. All others are power limited.

PDF (http://www.colorado.edu/physics/EducationIssues/podolefsky/EV_project/all_motors_2.pdf) of the graphs below.

http://www.colorado.edu/physics/EducationIssues/podolefsky/EV_project/all_motors_2.png

I'm doing this because there don't seem to be any standards, which makes it almost impossible to compare data from different manufacturers. I've tried to compile the best data I could find. As much as possible, these graphs are based on real dyno data (or what appears to be real dyno data). In some cases I've made assumptions to fill in gaps in the available data, e.g. assuming torque is directly proportional to current. It might not be perfect, since this data is all kind of sketchy.

Therefore: I am not responsible if you get one of these motors and find out it doesn't perform as expected. There are a million reasons this could happen, including bad data (don't blame the messenger!), bottlenecks in your system (such as weak batteries), etc. Just sayin'.

The graphs below show kW, motor torque, and adjusted wheel torque at 72V and 5:1 gearing on the left. On the right I adjusted the gearing so that all motors made 300 ft-lb at the wheel, and listed the gearing required.

Notes:

-Motors are running at different currents. I'm using the current limits that I could find from manufacturers. I think this is fair. If an AC-20 can handle 550A and the ME0709 can only handle 300, that's how they should be compared.

-The ME1003 is treated like an ME0709 with a 500A current limit (67% increase in torque, all else the same).

-I used the max efficiency listed. I did not adjust for changes to efficiency with RPM or current.

-The Dual Agni is assuming a parallel configuration. It looks impressive, but keep in mind it needs 800A to achieve this performance. Plot made by doubling torque.

-AC-20 96V plot was made by extending torque knee to 33% higher RPM.

Please let me know if you see anything glaringly wrong with this data. I'll keep trying to fix it up and get it as accurate as possible.

PDF (http://www.colorado.edu/physics/EducationIssues/podolefsky/EV_project/all_motors.pdf) of the graphs below.

http://www.colorado.edu/physics/EducationIssues/podolefsky/EV_project/all_motors.png

Plots below are for rated continuous current (under construction) and geared for 70 mph top speed.

- Note that the AC-20 is RPM limited to 70 mph at 8000 RPM. All others are power limited.

PDF (http://www.colorado.edu/physics/EducationIssues/podolefsky/EV_project/all_motors_2.pdf) of the graphs below.

http://www.colorado.edu/physics/EducationIssues/podolefsky/EV_project/all_motors_2.png