[AntronX]

So I bought myself a motor.

Specs:
- UQM 135 model SPM195-114-3.
- Brushless PM
- 135 KW peak power
- 340 N/m / 251 Lb/ft peak torque up to 2500 RPM
- 8000 RPM limit
- 270 - 425 Vdc (inverter input)
- 400A peak (inverter input)
- 50 Kg / 110 Lb
- 94% peak efficiency

My plans are to make controller for it, and use it to drive honda civic type car. Does anyone know of a good method to test magnet force to make sure this motor is not de-magnetized? I am thinking to attach lever with weight on the end to the shaft and apply known current to one of the phases and determine torque per amp. I need to determine if stator wired in delta or wye. Below are some pictures comparing this motor to AC24LS from Azure.

 

[AntronX]

Here is the data sheet.

 

[Sonikaccord]

Measure the line to neutral CEMF. According to the datasheet, it should be close to 335V at about 3000 rpm.

 

[AntronX]

Measure the line to neutral CEMF. According to the datasheet, it should be close to 335V at about 3000 rpm.

Where in the datasheet did you see this info? Is CEMF (BEMF?) directly proportional to magnet strength?I can rig up plastic shaft coupler to my cordless drill for a quick test. I got 14 days to return it.

 

[Hollie Maea]

Is CEMF (BEMF?) directly proportional to magnet strength?.

Field strength affects both Torque/Amp and Volts/RPM so you can measure either one.

 

[Sonikaccord]

Where in the datasheet did you see this info? Is CEMF (BEMF?) directly proportional to magnet strength?I can rig up plastic shaft coupler to my cordless drill for a quick test. I got 14 days to return it.

It's in the speed vs torque graph test data.

 

[AntronX]

Oh, I see it now. It's where the torque drop starts on the graph. I did not notice the 335Vdc test condition note at the bottom. Thanks guys, I will test this in a few days.

 

[major]

Measure the line to neutral CEMF. According to the datasheet, it should be close to 335V at about 3000 rpm.

Taking the no load generated voltage is the way to check flux level. However it is an AC signal so would be Vdc/√2, RMS. Better yet, put a scope on it and check the peak. And use line to line for the phase voltage. Neutral is unlikely to be accessible. Or connect the phases to a bridge rectifier and filter cap. That will then read the DC voltage.

 

[AntronX]

Taking the no load generated voltage is the way to check flux level. However it is an AC signal so would be Vdc/√2, RMS. Better yet, put a scope on it and check the peak. And use line to line for the phase voltage. Neutral is unlikely to be accessible. Or connect the phases to a bridge rectifier and filter cap. That will then read the DC voltage.

I got nice scope to try this on.
If I manage to spin this motor up to 500 RPM, should I expect (335*1.414) / (3000/500) = 78.9 Vp-p ?

 

[AntronX]

I found this shaft adapter from evtv store that appears to match the spline pattern on this motor. The drawing shows adapter spline minor diameter of 23.08mm, while measured motor shaft base diameter = 22.4mm. Adapter major diameter = 24.87mm, while I measured motor spline top diameter at 25.0mm. This means that I will either have to heat the coupler to press it on or shave down the motor shaft a bit.

The idea is to cut it in half and TIG weld appropriate piece to fit transmission shaft. I would like to use manual transmission in 3rd gear without clutch. Will I have problems welding this adapter to non hardened steel? Will I need to heat treat after welding?

 

[dedlast]

This means that I will either have to heat the coupler to press it on or shave down the motor shaft a bit.

In the description they say to heat the coupler to 300-some degrees and press it over the motor shaft.

B

 

[AntronX]

In the description they say to heat the coupler to 300-some degrees and press it over the motor shaft.

Would it be possible to pull the coupler off the shaft later using bearing puller tool? I would like to be able to try different motor coupling methods.

 

[Hollie Maea]

Would it be possible to pull the coupler off the shaft later using bearing puller tool? I would like to be able to try different motor coupling methods.

No. Interference fits are permanent.

 

[AntronX]

I got the motor spinning with power drill. Measured across 2 phases. Results are 62Vpp @ 52Hz. I could not directly measure shaft speed. Anyone know pole count these machines have? Seems like 8 poles.

 

[AntronX]

Found the way to get exact shaft speed. I placed the microphone next to spline shaft and rubbed piece of plastic against spline teeth. Fed amplified sound into 4th channel on the scope:

Since there are 24 teeth, its easy to calculate accurate shaft speed:

(24.88Hz * 5) / 24 * 60 = 311 RPM

Phase measurements are 49.2Vp-p and 42.02Hz. We know that from the torque graph, 335Vrms = ~3000RPM and 335Vrms * √2 = 473.76Vp-p, then:

473.76 / 49.2 = 9.6293
311 * 9.6293 = 2994.7 (RPM)

Right on the dot. This matches the data sheet perfectly. Looks like the magnets are fine. Below is my impromptu mess of a test setup.

 

[eldis]

Found the way to get exact shaft speed. I placed the microphone next to spline shaft and rubbed piece of plastic against spline teeth.

Cool I like your "let's use whatever is lying around" approach!

 

[Ai!]

wow! nice workbench! how did You used the audio mixer?)))))

 

[AntronX]

wow! nice workbench! how did You used the audio mixer?)))))

Thanks I used the mixer to amplify sound from headset mic while applying some EQ to keep the noise down. I then probed main output with the scope.

 

[AntronX]

I think I made a mistake by assuming 335Vdc inverter input directly translates to 335Vrms on motor's phases. Inverter voltage should become motor phase peak to peak voltage minus voltage drop in IGBTs. Correcting that part in my original extrapolation produces 2100 RPM at which I should get 335Vp-p. So it seems that BEMF does not directly equal torque drop off point on the chart, unless magnetic flux is stronger while the motor is spun unloaded. Could reluctance torque cause the knee on the chart start at 2500 RPM or some wave modulation magic going on?

 

[Sonikaccord]

Magnets are considered a constant flux source and should be independent of motor rotation.

How much IGBT voltage drop did you calculate?

I assumed a top and bottom switch drop of 2.5v and came up with 2950 rpm, based on your calculations.