Paul and Sabrina's Cheap 3 Phase Inverter (AC Controller) with Field Oriented Control

[e*clipse]

NBD - this is something I've been needing to do.

- E*clipse

P.S. Sent you an e-mail 'bout the motor

Originally Posted by MPaulHolmes

Thanks! Sorry for all that typing I just made you do. I do have the designspark files. my bad. I completely forgot that you sent them to me.

[e*clipse]

For folks interested in those MGR's - I'm posting some stuff about parts on the "hotrodding" thread.

[thingstodo]

Originally Posted by MPaulHolmes

Don't tell the instructables people, but this is just the basic AC control board that I already made. It doesn't do anything very fancy. Just reads currents, temperature (from one source), and throttle, and protects the IGBTs from desaturation and overcurrent and +5v and +24v undervoltage. There are a few extra pins, but a dspic30F4011 isn't going to do much more than that.

Paul - I received and unpacked to controller tonight

Pictures to follow. A screw terminal fell out of the controller when I picked it up so I guess I'll be doing some reading tomorrow, take the controller apart, and verify a couple of things

Kinda like Christmas!

[Astro]

Originally Posted by thingstodo

Paul - I received and unpacked to controller tonight...
Kinda like Christmas!

I am jealous.

I have seen pictures of my controller on the instructables page. So i know it exists.

I am keen to hear how the testing goes. It will be very on topic for the thread and i am sure there would be lots of lurkers waiting to see the results of all Paul's great work.

Paul just in case you were wondering, i am not so desperate to get my controller that you should feel any pressure to get the testing done quickly. I am happy to wait for you and thingstodo to get everything thoroughly sorted.

P.S. Paul, your instructable was a fantastic. This thread needs more pictures.

[MPaulHolmes]

I'm so glad it arrived! That will be a good motivator to get a .hex file done for the PI loop tuning. I can probably get it done today. For that you would need to run it in debug mode. I'll worry about making it all included in a single unified hex file later.

I included some things for interfacing to the outside world. I wasn't sure how you wanted to do that part. That's by far the thing I'm worst at (the packaging). Also my thinking on the current sensors was, if the 3 phase lines were mated to a yet to exist end plate, it wouldn't matter that the 3 current sensors were not bolted down (they could just be around the cable). I bolted it with astro's, but it took a LOT of bending (the picture doesn't do it justice). I'm still not sure which way is better. I didn't want a lot of tension on the sensors.

Astro: kablamee!



That's my favorite one. The copper is so clean looking!

[thingstodo]

Originally Posted by MPaulHolmes

I'm so glad it arrived!

Me too!

I included some things for interfacing to the outside world. I wasn't sure how you wanted to do that part.

That's the 4 cable glands and the 4 x 6 terminal strips, right?

Also my thinking on the current sensors was, if the 3 phase lines were mated to a yet to exist end plate, it wouldn't matter that the 3 current sensors were not bolted down (they could just be around the cable)

Good idea! I'll see if I can cobble together something for that end-plate.

.. If I use 1 end plate on the inside, then the current sensors go around the cables, then another end plate on the outside, the current sensors should not rattle around. Maybe I can use some packing foam to keep the each of the current sensors centered around the cable. It may not be more accurate, but it should be more consistent. ...

[MPaulHolmes]

I have tested the LEMs with moving the wire around the inside of the window, and it was within 1% (at least with a LEM Hass 50-s with 3 wraps through the window, to cause it to behave like a LEM Hass 16.66666666-s). So, it couldn't hurt, but wouldn't be critical I don't think.

Crap, I thought I sent 5 of those cable glands. I'm sorry about that. As a side note, it's possible they should have gone over the cable before adding the lug. But the gland thing may still fit over it.

[Astro]

Originally Posted by MPaulHolmes

...Also my thinking on the current sensors was, if the 3 phase lines were mated to a yet to exist end plate, it wouldn't matter that the 3 current sensors were not bolted down (they could just be around the cable). I bolted it with astro's, but it took a LOT of bending (the picture doesn't do it justice). I'm still not sure which way is better. I didn't want a lot of tension on the sensors.

Paul, how about turning the lugs that connect the cable to IGBT's upside down?
That should lower the cable a bit so that it is a little more in line with the current sensor apertures. Might not be doable but in the pictures it looks like there might be enough clearance.
Another thing would be to chop up a thick kitchen chopping board (nylon?) and make a spacer or two to sit under each of the sensors to raise them up to be more in line with the cable path.

P.S. Yep, I like kitchen chopping boards, they cut and drill as easy as wood, are non conductive, available everywhere and are super cheap.
I may even look at making the end plates for the enclosure from a couple of large chopping boards. They are usually thick enough that screws from outside the enclosure could be screwed into the edge of the chopping board.

[Astro]

Originally Posted by thingstodo

... If I use 1 end plate on the inside, then the current sensors go around the cables, then another end plate on the outside, the current sensors should not rattle around. Maybe I can use some packing foam to keep the each of the current sensors centered around the cable. It may not be more accurate, but it should be more consistent. ...

How about some plastic cable ties, should keep the sensors from sliding on the cable.
Put the cable tie through the sensor going in on one side of the cable and out on the opposite then diagonally over the top. Then another one at 90 degrees to the first so you get a crossover of the cable ties. That should keep them from moving anywhere.

[MPaulHolmes]

The 2 gauge cable is a pretty tight fit, but a cable tie wouldn't be a bad idea.