Paul and Sabrina's Cheap 3 Phase Inverter (AC Controller) with Field Oriented Control - Page 272 - Fuel Economy, Hypermiling, EcoModding News and Forum

thingstodo · 03-30-2016, 02:43 PM

Quote:

Originally Posted by MPaulHolmes

I might know what the problem is. Remember how i had to change the PI code so that it ALWAYS did the PI, even at zero throttle in the case of the permanent magnet motor? Some weird behavior happened with your motor when it went to zero from nonzero. The slip speed and electrical speed went way negative, and then WAY WAY positive for an instant. I'm thinking that's because your code still has the old way of dealing with transition from nonzero throttle to zero. I need to get you an updated .hex file.

I think you still need to run the PI at zero speed so that if you let off the brake on a hill .. there is regen braking if you have the throttle set that way.

It surprised me that the shaft spun slightly backward .. I just thought it was very aggressive.

MPaulHolmes · 03-30-2016, 02:49 PM

Quote:

Originally Posted by thingstodo

I think you still need to run the PI at zero speed so that if you let off the brake on a hill .. there is regen braking if you have the throttle set that way.

I think you are exactly right. I did a "leaf only" code that I haven't tested yet. I would like to do an "induction only" code too so things don't get so out of control with so many cases. I'll do that and get it to you with the "PI AT ZERO" running.

thingstodo · 03-30-2016, 03:56 PM

Quote:

Originally Posted by MPaulHolmes

I think you are exactly right. I did a "leaf only" code that I haven't tested yet. I would like to do an "induction only" code too so things don't get so out of control with so many cases. I'll do that and get it to you with the "PI AT ZERO" running.

Have you set version 1.0, or 1.0a, or whatever ... a stable version in any case ... so that someone who builds the board can load it in as known good ... while you increment the testing version to version 1.1 and keep changing stuff?

And I would

humbly

inquire into the state of the DC controller and AC controller backups .. dropbox? .. email to me or someone else?

You just have so MUCH FUN changing and updating ...

coleasterling · 03-30-2016, 07:55 PM

MPaulHolmes · 03-30-2016, 09:35 PM

A thicker plate doesn't have any down side that I know of, other than maybe costing a little more. It would help with the capacitor cooling. It's just that I have been using children's safety scissors for cutting out the sheets. haha. 10 mil copper is probably enough in terms of current carrying capacity, but there's no bad side of thicker copper. I will most likely use 32mil copper in general in the future when I get the sheets made professionally. I actually just finished a couple 1400amp 350v DC controllers that used the 32 mil copper sheets, and I really like how they turned out. (thingstodo has one of them.)

thingstodo · 03-31-2016, 10:31 AM

Quote:

Originally Posted by coleasterling

Is there any benefit or detriment to going with thicker copper than what you've got right now? Ability to clamp to the ring cap, maybe? It would be far easier for me to manufacture the sheets if they were thicker. I like the idea of a more rigid "plate" instead of "sheet" as well.

Thicker copper weighs a bit more .. but we're talking about an ounce or two.

How thick can the copper be and have Paul still bend it as required?

coleasterling · 03-31-2016, 10:42 AM

thingstodo · 03-31-2016, 12:26 PM

Quote:

Originally Posted by coleasterling

It really depends on what bend radius you want. With copper, you typically want a bend radius a little over the material thickness, at least in the thicknesses we're working in. So for a 20gauge sheet, you'd want around an 0.040" radius. That should be pretty doable even with a home-built brake.

I don't think that the bend radius is critical. As long as it is reproducible, the hole locations and bend locations can be adjusted.

We had to ream out the holes on the top copper sheet during construction of my DC controller - the bend was not perfect, and the holes were lined up for the lighter gauge.

Are you getting the holes drilled as well? If so, it would be great if the bends were marked. I don't know what the convention is - perhaps a scribed line on the outside of the bend, showing begin and end of the bend? Or maybe a bit of slop for non-perfect bend alignment (perpendicular) ... 0.125" maybe?

This is just me guessing - I'm sure you have a solution already!