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

[ricemodder]

Got the controller running thanks to Paul. Abused it and it still going!!

[ricemodder]

Originally Posted by ale0502

Hi everyone,

It´s placed on the circuit three comparators for compare the "under current" of the LEMs measurements.
What is the function of that?
I understand de high current, but not the under current.



thanks

Hi,

The label 'under current' is used to represent negative values. The lems have a nominal output of about 2.5 volts - this represents a 0 amp value. if the voltage is below this, the current is negative.

The three comparators are used to similar to the high current but compare the negative current or low side fet ids.

[ricemodder]

Originally Posted by wehzeh

I got the code loaded on, what's a good way to test it Before I solder it on?

My PICKit 3 also can't find the PIC (which I already soldered on), what components are needed for me to be able to talk to it?

Power it up on gnd and vcc. Check and see if there is a square wave on the output. If you don't have a scope, it should show about 2.5V rms dc.

[wehzeh]

Originally Posted by ricemodder

Power it up on gnd and vcc. Check and see if there is a square wave on the output. If you don't have a scope, it should show about 2.5V rms dc.

Haha, got over that a while ago. I'm working with Paul to slowly extract all the info he has and reorganize everything. If you have anything to add/suggest, drop me a line!

[MPaulHolmes]

I got a new board made! I just want to mention that I have really appreciated having Astro's controller for testing. I"m going to solder him one of the new boards.

This one includes voltage monitoring, a 2nd temperature, and also a brake regen "throttle". And it's all 1206 and 1210 suface mount resistors and capacitors. No 0603 this time.

The board was specifically designed so that all the holes in the aluminum plate could fit in one drilling run of my mill (so I don't have to do any precise moving of the plate). Also, I'm going to try this capacitor:
http://www.mouser.com/ProductDetail/...7nU%2faA%3d%3d (or 2 or 3 of them)

It makes the copper sheets SUPER easy to make. YOu just do 2 pieces with a cross section like this:
][, and a little piece of nomex isolation material in the middle. LIke this:
]|[
Then, the ']' is B+, and the '[' is B-, and the top of the caps get bolted to the enclosure. Much easier access and assembly. And then the controller area is more like 8" x 11.5" (or maybe 11"). I would take a picture of a couple of the boards that are almost soldered, but my stupid apple phone is a daughter of debauchery, and needs to be flushed down the toilet. Whenever I take a picture and "email it to myself", it makes the whooshing sound, and sometimes weeks can go by before the picture shows up. haha. And it only lets me take like 13 pictures at a time, because it's always full, and you can't get a friggen SD card in it.

[mrbigh]

We want to see pictures of the newest member of the controller's family..........

[MPaulHolmes]

Well, something crazy happened! I emailed the pictures to myself on the phone, and they emailed... Oh yes, it also has reverse polarity protection, as well as a fuse, and overvoltage protection on the input. So you can put up to 60v on the 24v supply in backwards and nothing bad will happen, and you can put 60v in forwards on the 24v supply and nothing bad will happen, except for getting a new fuse. haha.

It should be able to drive IGBTs with up to around 16amp of current pulses, but I always use 3.3Ohm gate resistors. The 6 IXDN604si's are an upgrade. They are the more expensive ones with a metal underside so that you can put more power into each isolated supply. Of course, it's not needed unless you are using 1200v 600amp IGBTs, but it's nice that it's available. They stay very cool.

[ricemodder]

Wow. That board looks great!

I've been abusing the first revision and it's running fine at 400 VDC. Blew some fets a while back and still the gate drives were working. I didn't expect that.

[wehzeh]

Any back compatibility for new features? As long as the pinout for the PIC didnt change that should be the case. Just run new wires to the pins and put the rest of the new circuitry on a new sub-board or something.

[MPaulHolmes]

It's mostly the same pinout. There are one or 2 differences. A simple conditional compile would take care of it.