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

[e*clipse]

For the round design the phase sensors ( outputs ) are each on the quadrant of that big 8 1/2" diameter capacitor. So, they are about 6" apart.

The boost input would be handled exactly like the outputs, so it would be about 6" away from any output. The input would be seeing twice the current (bigger field) for a 2X booster.

I would guess that 6" should be sufficient for not needing any shielding, but these are the noisiest wires in the car. I don't know about the sensitivity of other parts of the controller; it just seems like a "better safe than sorry" situation.

- E*cipse

[MPaulHolmes]

Originally Posted by thingstodo

Sep 24 - Oct 28 is quite a while between updates!
Here is the update for Nov 1 - actual testing is done!

That is awesome! I don't know what the data was that was being outputted when you typed "a". I changed it so many times. We need just a serial stream. I'm going to add that back in. Awesome job!!

[e*clipse]

Paul -

Could you send me either a BOM or a design spark library of the newest board?

I don't have any of the component info for the parts on the "ACControlAndDriverBoard1" which I'm using as a base for the new design.

It would be a huge help to at least know which components you used - I can fake it for the resistors and stuff like that, but transformers, etc get very specific.

Thanks a bunch,

E*clipse

[e*clipse]

Thanks a bunch!

It works.

- E*clipse

[thingstodo]

Originally Posted by MPaulHolmes

I don't know what the data was that was being outputted when you typed "a". I changed it so many times. We need just a serial stream. I'm going to add that back in.

I think there was a capture of the voltage and current - but I was looking for the rpm indication at the end.

If you can make the serial stream the same (or at least the first part the same) as for the Cougar, I received an update to RTD Explorer that I can try out. If the first part is the same and you add extra data as required to the end .. that should work, right?

I have more data from Nov 2 that I need to post. But it brought up some of the deficiencies of my setup:
- AC amps - I have one clamp-on meter, so I kinda need to monitor the AC out of or into the controller .. unless that's part of the serial stream
- AC voltage - I have a multimeter that can be used for that, but it needs to be in the camera's field of view and I'd have to play back the video and write down the numbers
- DC pack voltage - I can use another multimeter for that
- DC pack current - I can use an uncalibrated shunt that I have. It should be close. 100 mv = 100A so I can use another multimeter to show mv and it should convert directly to amps
- controller temperature and motor temperature - I can use a handheld infrared but it will not be continuous readings
- temperature of the various terminal connections - again, use a handheld?

That leaves the DC motor part. If I get the cougar running, I have most of what I need from RTD explorer. Except for the temperature of the brushes .. which I need to monitor with a handheld. The input power to the system is not as important (to me) - do you agree?

The biggest issue that I have not talked about is cooling. There is liquid cooling for the AC motor, but I need to come up with a chill plate for the AC controller and whatever DC controller I use. That would be the more permanent solution. I could use suggestions for a cheap and easy cooling loop. These tests should be under half an hour long. I have a forced air blower for the DC motor and a shroud. That should do for a half-hour test.

Cheaper - I have searched the local hardware stores - naptha is still sold in metal 1 gallon containers. A metal container like that filled with water may work - no pump and no circulation but it would take a while to heat up the water inside. I could put the rectangular container on it's side and clamp a controller to it .. maybe a bit of thermal grease to get a good thermal connection?

[e*clipse]

Originally Posted by thingstodo

** cut **

The biggest issue that I have not talked about is cooling. There is liquid cooling for the AC motor, but I need to come up with a chill plate for the AC controller and whatever DC controller I use. That would be the more permanent solution. I could use suggestions for a cheap and easy cooling loop. These tests should be under half an hour long. I have a forced air blower for the DC motor and a shroud. That should do for a half-hour test.

Cheaper - I have searched the local hardware stores - naptha is still sold in metal 1 gallon containers. A metal container like that filled with water may work - no pump and no circulation but it would take a while to heat up the water inside. I could put the rectangular container on it's side and clamp a controller to it .. maybe a bit of thermal grease to get a good thermal connection?

- How about pre-chilling a big aluminum chunk? Just stick it in the freezer for a while, then quick bolt it to a spreader plate for the test.

- I'm curious about this 'cause I want to try pre-cooling the battery pack. There's a HUGE mass/thermal mass in a battery pack.

- E*clipse

[Piotrsko]

My vote is spray freeze or C02 fire extinguisher and big aluminum plate. Block of dry ice underneath?

[thingstodo]

Originally Posted by e*clipse

- How about pre-chilling a big aluminum chunk? Just stick it in the freezer for a while, then quick bolt it to a spreader plate for the test.

- I'm curious about this 'cause I want to try pre-cooling the battery pack. There's a HUGE mass/thermal mass in a battery pack.

- E*clipse

The biggest chunk of aluminum I have is the base of the Renault/Better Place pack .. but I don't think there is enough flat surface to mount to the controllers.

I'll see what I have kicking around. And if it fits in my freezer

If it's too big for the freezer, outside is 35 - 45F right now. That should be cold enough to pre-chill, depending on how big it is.

[thingstodo]

Originally Posted by Piotrsko

My vote is spray freeze or C02 fire extinguisher and big aluminum plate. Block of dry ice underneath?

I think spray freeze qualifies as quick. Not so sure if it's cheap. At $15 per 10 oz can on Amazon.

How many cans I would need to use .. ? .. no idea

I have paid for refilling CO2 cylinders for fire extinguishers. I KNOW that is not cheap around here.

[MPaulHolmes]

One option is milling channels somehow haha, and then bolting a thin aluminum sheet to the base, somehow sealing the channels so they don't leak, and then somehow attach a hose to the base plate edge.

Or you could do the testing with the base plate sitting in water. It could get to 100 degC, and then would definitely hold there, because it takes a ton of energy to evaporate water.