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

[MPaulHolmes]

I changed some code on the Maximum power point tracker/charger for the solar panels (5.6kW worth), so the go kart can now charge up nice and fast, right from DC!

https://www.youtube.com/watch?v=dxp8kX_golA

[MPaulHolmes]

Originally Posted by arber333

Well i am almost there and luckily i remembered...

When i couldnt install PCB one way, due to current sensors, i rotated it so i now have IGBT contacts facing backwards. Eg. G1 E1 on IGBT is now G2 E2 on PCB and vice versa. Please advise Paul. Would that cause harm to IGBTs? Or is the switching so symetrical nothing would happen.
First picture is with contacts connected. On the second i tried to criss cross them so they would plug in ok. Which would be better?

Also is the wire length important? I made twisted wire, but with crossed cables wire length is more than i planned. at least for comfortable installation. Would wire length be an issue? Should i add one TVS diode directly to IGBT GE contacts? Wire length is now 10cm from PCB to GE.

Arber

Make sure they are crossed. One drives the high side and one the low side. Right now the high side is plugged into the low side and vice versa. That would be very bad. very very very bad.

So, as long as the IGBT on the right and the middle one have the current sensors, it should be OK.

[kalidasbala]

I could not quote, as I have less posts.
That was awesome kart Paul, I like the skidding part.

How easy is it to change the regen? Do we need to change the code or is there any external adjustment? An external knob would be good!

[kalidasbala]

In the new board (v0.3), is the desaturation detection need to be done. Connecting "collector of IGBT1H to emitter of IGBT1L" via a wire? Or is it incorporated in the new board?

[kalidasbala]

Originally Posted by arber333

I think desat is there on PCB, i dont see any special connectors to feed from C.

Paul may i ask how did you connect contactor and precharge relais? I have them connected to 2x 12V relais outside with one cable +12V as trigger for each relay. The - from each connector goes to inverter case as GND. Would that be ok? Saves on contact place as i have space for only 20 connections.

tnx

A

Yes, even I would like to know how the connection is. If there is a wiring photo, it would help.

[MPaulHolmes]

https://www.youtube.com/watch?v=8gc9...ature=youtu.be

[MPaulHolmes]

Wait on applying battery voltage. Make sure we are on the same page for contactor control.

First, it goes like this:

+12v ---------------------- contactor in (on board)
contactor out(on board) -------------- contactor coil PLUS

contactor coil ground ------------- +12v battery ground.


You will also need to run the angle offset test, and stuff like that.

[kalidasbala]

Paul, what is the battery pack size for your go-kart? How fast the solar charger is able to directly charge the batteries - charge rate?

[MPaulHolmes]

Battery is 5.6kwh, 93v A123 cells from a spark EV. Capable of about 100kw! Maximum charge rate during the right time of year should be around 50 amps from the panels.

[thingstodo]

Originally Posted by arber333

I ran the inverter with 40V. everything was good, so i tried to start your pi test. It was succesfull for 40V.

Sounds good. If I remember, the motor tuning values change a bit when you change voltages. But the numbers you got for 40V should work OK with higher pack voltage. running the PI test at higher voltages will get you more aggressive acceleration.

Then i ran offset test... Well motor doesnt want to spin so should i leave it there? Motor jumps a little but it doesnt move much.

I don't remember an offset test. Is that for the encoder?

The sound of water flowing is disconcerting. I dont have reference whether pwm is working or not. I dont have any cooling for inverter yet...

So the PWM sounds like water running? I had a couple of different sounds. A whine was the first one, then Paul put in the random frequency and it sounded more like a white noise generator. But no running water noise.

I ran the inverter with no water cooling during my tests. It will shut itself down on high temperature and on high current. I was not moving a car or anything, but I did have some load on the motor.

Is 40Vdc good voltage or is it too small. I just took a pack from front of my car since it was the easiest thing to do. My friend with 160V car will stop by tomorrow and i can connect inverter to 160Vdc. Would that be better?

I ran a bit higher - I think around 50V (48V lead acid pack) at first. The rest of the time I was running at 128V, which is my pack voltage. I don't know if running the offset needs more voltage or not ...

Paul - what does the offset do?

Arber333 - do you have a list of what you have done, so far, written up? I will be working with the new AC controller board in the new year, connected to some older and smaller IGBTs ... I guess I should go through the thread again and see what's been happening lately!