Francisco's Electric Pajero

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francisco.shi
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Re: Francisco's Electric Pajero

Post by francisco.shi »

Finally got the last phase in.
Top view all phases. (Inverter side)
Top view all phases. (Inverter side)
20200617_175535.jpg (1.91 MiB) Viewed 283 times
Bottom view. (Shaft side)
Bottom view. (Shaft side)
20200617_180031.jpg (1.69 MiB) Viewed 283 times
Now the wires line up with the IGBT module output tabs.
Output terminals and IGBT module.
Output terminals and IGBT module.
20200617_175820.jpg (1.73 MiB) Viewed 283 times
All I need to do now is join the neutrals, tie up all the coils with string, apply varnish and crimp the output terminals.

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brendon_m
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Re: Francisco's Electric Pajero

Post by brendon_m »

Looking good.
I'm very impressed, not to mention interested to see how it turns out

francisco.shi
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Re: Francisco's Electric Pajero

Post by francisco.shi »

I am confident it will work as expected.
I have already tested the power stage with a single IGBT module to 400A 380v with no problem at all. For this winding i will have two IGBT modules so the load on each module will be the same on each module as already tested. The current sharing will be pretty close to half because each module is driving its own winding.
The output torque will be the same as before. The only difference is it will spin to twice the speed as before before it starts dropping in torque. So it should roughly give me double the power.
As for the top speed I will still run within the motor specs.

francisco.shi
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Re: Francisco's Electric Pajero

Post by francisco.shi »

I finally got the motor almost finished.
Inserting wedges.
Inserting wedges.
20200628_104416.jpg (1.66 MiB) Viewed 105 times
Wedges all in.
Wedges all in.
20200628_115959.jpg (1.7 MiB) Viewed 105 times
Windings tied.
Windings tied.
20200703_001031.jpg (1.8 MiB) Viewed 105 times
Other side windings tied up.
Other side windings tied up.
20200703_001018.jpg (1.6 MiB) Viewed 105 times
Will post more pictures later of the assembled motor.
Now just need to put the terminals to the transistor pack.

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jonescg
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Re: Francisco's Electric Pajero

Post by jonescg »

Looks legit! I always wanted to try winding a motor for the learning process.
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francisco.shi
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Re: Francisco's Electric Pajero

Post by francisco.shi »

The more I work on it he easier it gets.
Here is a video from Indian university explaining winding of electric motors.

Reminds me of a lecturer I had at uni.

francisco.shi
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Re: Francisco's Electric Pajero

Post by francisco.shi »

I did a bit more work on the motor today. I put the terminals and installed the power stage from the inverter.
Motor with inverter output stage installed.
Motor with inverter output stage installed.
20200704_191804.jpg (1.36 MiB) Viewed 62 times
Another view.
Another view.
20200704_192049.jpg (1.33 MiB) Viewed 62 times
The next step was to measure the back EMF and compare it to the old motor.
Old winding response at 1110rpm
Old winding response at 1110rpm
20200704_183844.jpg (1.33 MiB) Viewed 62 times
And here is the new winding.
New winding response at 1095rpm
New winding response at 1095rpm
20200704_184210.jpg (1.35 MiB) Viewed 62 times
The old winding was short pitch wound and the new is full pitch wound.
The difference is with short pitch the 3rd and 5th harmonics are almost eliminated. You can see that the old winding produces a perfect sine wave. The full pitch winding has the disadvantage of having more harmonics but has the advantage of using the full lux from the magnets which will result in slightly more torque capability. You can see the output wave is not as cleaned. The peak of the wave has a small lump.
And the last thing to confirm I got the two parallel windings wound with the correct phase I connected two terminals on the same phase together and measured the voltage between the two terminals on another phase and spun the motor. If I got it right there should be no voltage between them. And here is the result
(See next post. I couldn't add so many files)
I have a Hyper9 motor I am making an adaptor for so I though I should do the same test and see what it is like. I was curious as to the back EMF constant (volts/rpm) and here is the result.
Hyper9 response at 1117rpm
Hyper9 response at 1117rpm
20200704_193526.jpg (1.36 MiB) Viewed 62 times
The Hyper9 is a 4 pole motor so the frequency is lower.
It is difficult to say anything good about this motor without having to lie.
The harmonics on this thing are horrendous. No wonder they overheat.
The other problem will be trying to measure the angle of the current when doing the Parke transforms. I can't imagine how hard it must be to get the inverter to work correctly.
Here is a side by side view of the two motors.
Hyper9 vs my motor comparison.
Hyper9 vs my motor comparison.
20200704_193954.jpg (1.56 MiB) Viewed 62 times

francisco.shi
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Re: Francisco's Electric Pajero

Post by francisco.shi »

Here is the voltage between the two parallel windings.
Voltage difference between two parallel windings.
Voltage difference between two parallel windings.
20200704_184457.jpg (1.29 MiB) Viewed 62 times
As you can see it is negligible.
I am quite happy with the results so far.
Now I need to finish the logic board and test it and compare it to the original winding.
I am pretty confident the results will be as expected.

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coulomb
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Re: Francisco's Electric Pajero

Post by coulomb »

francisco.shi wrote:
Sat, 04 Jul 2020, 20:27
And the last thing to confirm I got the two parallel windings wound with the correct phase I connected two terminals on the same phase together and measured the voltage between the two terminals on another phase and spun the motor. If I got it right there should be no voltage between them.
Neat. Was this before closing up the motor and crimping the final terminals?

Really interesting work, thanks for sharing.
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francisco.shi
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Re: Francisco's Electric Pajero

Post by francisco.shi »

I had to assemble the whole motor including crimping the neutrals which are inside so I could spin the rotor inside the stator to get a voltage waveform.
The inverter has two IGBT modules in parallel in order to get the current capacity. But to make things more effecient I run one winding per IGBT module. This way the winding resistance acts as a sharing resistor. This allows the maximum current rating of the IGBT to be used.
IGBTs have negative temperature coefficient which means I can not just connect them in parallel or one will start taking more current than the other and eventually blow up. To get around this problem you can go several ways. One is derate the current capacity of the pair to less than double of each device. Another is to get match devices (unlikely to happen unless I get them direct form the manufacturer) and the last one is to add a resistor in series with each device. The resistor will generally help to keep the current thru each device shared more evenly. The problem with the last method is you increase losses. What I have done us use the winding resistance as sharing resistor.
The tricky part was that I had to wind one winding back to front so that the terminals ended in the same spot. If I had wound them the conventional way I would have ended up with the terminals of each of the parallel windings on opposite sides of the motor (which would have been very inconvenient for packaging)

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coulomb
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Re: Francisco's Electric Pajero

Post by coulomb »

francisco.shi wrote:
Sun, 05 Jul 2020, 08:44
But to make things more efficient I run one winding per IGBT module.
Duh! 6 wire bundles coming out; I somehow missed that. And of course you told us about the separate windings earlier. Thanks.
Nissan Leaf 2012 with new battery May 2019.
5650 W solar, 2xPIP-4048MS inverters, 16 kWh battery.
1.4 kW solar with 1.2 kW Latronics inverter and FIT.
160 W solar, 2.5 kWh 24 V battery for lights.
Patching PIP-4048/5048 inverter-chargers.

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