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

[arber333]

ok Paul

I tried to test with motor as type 2
no luck so far. i can run PI test and motor spins a bit and then i get the value of Kp, Ki and PI.
When i try to start angle offset test nothing happens.

I was thinking, is this maybe encoder originated error. Remember, outputs are open collector 5V. So i put 4K7 resistors to the lines. That is inverting signals no? Now A and B signals are changing fast so micro is seeing them as they are. But Z signal happens very quickly ONCE per revolution. Now that means that Z line is just standing there high at 5V all the time. Wouldnt that cause misunderstanding in your encoder logic? Do you have to invert reading of signals for me?

EDIT I tried again with motor type 3 set and now axle is rotating at 1 deg intervals. Then some 10min into test it suddenly spun up and then stopped and again went rotating slowly per deg. Did you think that i should hit off here as it stopped spinning? Its kind of watching bad horror movie. When you get bored, monster jumps at you from the shadow...

Maybe i will just put another 24V inline to get 64Vdc and try again...

[kalidasbala]

I was able to get hold of some IGBT at reasonable price. Finding a film cap is getting painful. Is there an alternative, how good are elcaps? If I use elcaps, what precautions needs to be taken?

[MPaulHolmes]

Electrolytic caps have a higher ESR and stray inductance, and lower ripple current rating, but should be fine for an inverter. It might be a good idea to add a snubber cap or 2 along with the electrolytic, and don't run too high a voltage. Maybe for 600v IGBTs, 300 or 350v max?

[motorulf]

Hello from norhtern sweden!

I have been reading this thread for some time now.
I ordered a populated and tested card from Paul a little while ago. Version 0.3.

I have a few questions.
The board has CAN-bus pins on it, is that supported in software? Or is it a future feature?
I have read the latest firmware source codes i could find (may 2016) and i couldn´t find anything about CAN in them.

Also, it has 2 pins called Voltage, is this actual HV voltage?

I wish to use this controller in my Think City -08. That car has a Vehicle Control Unit to control instrumentation. It would be great if this controller could send CAN messages directly to that VCU.
An other possibilty is to use the RS232 to talk to an other microcontroller that gathers all information and sends CAN to the VCU. is that doable?

Also the voltage input i wish to get data from, it would be great to use it for SOC.

Thank you all for all your effort on this controller, i cant wait to put in my car
I am building the batterypack now. 176 LEV50-cells, Lithium instead of the broken zebra-battery that orginally came in the car

[kalidasbala]

Originally Posted by MPaulHolmes

Electrolytic caps have a higher ESR and stray inductance, and lower ripple current rating, but should be fine for an inverter. It might be a good idea to add a snubber cap or 2 along with the electrolytic, and don't run too high a voltage. Maybe for 600v IGBTs, 300 or 350v max?

Thanks Paul. I am planning on 600V 2000uF elcap and 600V 2uF snubber.

Do I need a pair of these set or just one elcap+snubber is good enough?

I am planning to run a 220VAC motor for test purposes.

Also I assume I can use a pot instead of a hall-effect throttle. If so, can you suggest me a pot that I can use with the board.

Update: Ok, this is what I got 450V 2200uF elCap and 1.5uF 1000V snubber caps (2 of them). Hope it is ok for an IGBT 600V 400A (mitsubushi- powerex)

[MPaulHolmes]

Originally Posted by motorulf

Hello from norhtern sweden!

Hej Hej!

Originally Posted by motorulf

I have a few questions.
The board has CAN-bus pins on it, is that supported in software? Or is it a future feature?
I have read the latest firmware source codes i could find (may 2016) and i couldn´t find anything about CAN in them.

Also, it has 2 pins called Voltage, is this actual HV voltage?

I haven't done the software for it yet. Well, I have, but it was for a different context, so it would be relatively easy to cut and paste the code. Although, there's no support right this second for specific CAN frame parsing or whatever. It's just "send data to the universe, and whoever has the mask to accept it, accept it! And I can also receive bytes!"

The voltage pin takes the stepped down voltage from the high voltage DC bus. It must be stepped down to 0-2v or 0-3v max. For example, if you are using 600vDC (176 lithium batteries in series, rounded to 600 to make the math easier), you would need a 300k resistor that can handle 600*600/300,000 watts, so maybe three 100k, 1watt resistors in series. Like this:

+600v ---------- 300kOhm 2watt or 3watt ---------------- Voltage + pin.
600v ground ------------------------------------------- Voltage negative pin.



Yes, you can use the high voltage data and use it for SOC. That's also something that would have to be added to the software, but wouldn't be too big of a deal.

-Paul

[MPaulHolmes]

Originally Posted by kalidasbala

Also I assume I can use a pot instead of a hall-effect throttle. If so, can you suggest me a pot that I can use with the board.

Update: Ok, this is what I got 450V 2200uF elCap and 1.5uF 1000V snubber caps (2 of them). Hope it is ok for an IGBT 600V 400A (mitsubushi- powerex)

YOu can try it out, and if under heavy load, the capacitor gets too hot, you could always add another. 1 test is worth a thousand theories!

Yes, to use a pot instead of a hall effect throttle, you would include R101 (maybe 1k or whatever), and use a 4.7k or whatever resistor for R73. Then, you could use a 0-5k pot or 0-10k pot, or whatever. YOu would then use the pin labeled "OUT" on the HALL connection, as well as the pin labeled POT that is just sitting outside the HALL connection. You would have no use for +5v and gnd for a pot. You just need the 2 wires "out" and "pot".

[arber333]

Well i hope you all had merry christmas and i wish you happy transition to new year 2017, to be close to your families and successful.

Originally Posted by kalidasbala

Thanks Paul. I am planning on 600V 2000uF elcap and 600V 2uF snubber.

Update: Ok, this is what I got 450V 2200uF elCap and 1.5uF 1000V snubber caps (2 of them). Hope it is ok for an IGBT 600V 400A (mitsubushi- powerex)

Right now i use 2x 100uF 800V in paralel. FFVE6B0107KJE AVX Film Capacitors 800volts 100uF 10% (1 PER) | eBay
They are AVX film caps, very fast and one can sustain 90A in DC link function. I put them in my car instead of two elcaps 4700uF 500V in series and i can see difference instantly. Theres more energy available for instant acceleration, otherwise no special difference.

And of elcaps... if you use them, try making a good rail connection, not wire from elcap to rail. Once my wires from caps to rail melted due to my overzealous testing of low voltage motor operation. I threw elcaps out and i use exclusively film caps now connected with at least 1mm x 15mm copper rails.

Snubbers i use 3x 2uF 1200V. RoT is cca 0,6uF per 100A of IGBT. They have to be fitted directly to IGBT +/- rail contacts to be of any use.

[kalidasbala]

Originally Posted by arber333

Well i hope you all had merry christmas and i wish you happy transition to new year 2017, to be close to your families and successful.



Right now i use 2x 100uF 800V in paralel. FFVE6B0107KJE AVX Film Capacitors 800volts 100uF 10% (1 PER) | eBay
They are AVX film caps, very fast and one can sustain 90A in DC link function. I put them in my car instead of two elcaps 4700uF 500V in series and i can see difference instantly. Theres more energy available for instant acceleration, otherwise no special difference.

And of elcaps... if you use them, try making a good rail connection, not wire from elcap to rail. Once my wires from caps to rail melted due to my overzealous testing of low voltage motor operation. I threw elcaps out and i use exclusively film caps now connected with at least 1mm x 15mm copper rails.

Snubbers i use 3x 2uF 1200V. RoT is cca 0,6uF per 100A of IGBT. They have to be fitted directly to IGBT +/- rail contacts to be of any use.

Merry Christmas!

I will get another snubber, as it is a direct fit to the IGBT. I am unable to find film caps here - still searching. As a backup let me get another elcap as well, until I find a decent film cap.

Yes the plan is to use the copper rail for now. Still searching for the current sensor, & contactor, hope to get hold of them soon.

[motorulf]

I see there is an unused input on the dsPIC, as i understand the code it was planned for use as a regen throttle input but i was never used because the PIC cannot read both this and the neighboring temperature input, at least not if both are analog inputs.
So i am thinking, that pin could be used as a digital input for controlling reversing, a feature i really wish to have

So, i was poking around in the code a bit and edited it for my liking.
Im not shure about this though, im am not a programmer or an EE nor have i fully understood the currentRadiusRefRef variable and the sign variable.

I just posting this as an idea for people to have thoughts on, or maybe laugh at
Do NOT USE the code!
Do you guys think this will work?

Also an other idea i had late last night was to build a small board with connector that fits on the icsp header, instead of using the regen_throttle input. This board would use 2 pins (PGC/PGD), one for input of reverse switch, and one for a relay output.
My car has an gear lever that has a solenoid in it, so it can not move between different gears at the wrong moment.
Actually this is just a BIG switch as there is only 1 gear in the box, and all control is done in SW in the original controller...
anyway... thats what the relay is for
Pros with this: it simple to build an extension board that plugs in to existing controller board.
Cons: by using these pins you can not do debugging via icsp anymore. at least not as long the pins are defined as I/O in SW.
that is how i understand it, but i am wrong quite often

		if (RPS_times16 < 8) {  // if less than 0.5 rev per second, make sure there's no regen. Also allow changing into reverse
			if (currentRadiusRefRef < 0) currentRadiusRefRef = 0;
                if (I_PORT_REGEN_THROTTLE == 0) {   //check input for reverse switch
                    reversing = 1;
                {                
                else{
                    reversing = 0;
                }
            }
		}
        if (reversing = 0){
		if (currentRadiusRefRef < 0) {
			currentRadiusRefRef = -currentRadiusRefRef;
			sign = -1;
		}
		else {
			sign = 1;
		}
        }

        if (reversing = 1){
		if (currentRadiusRefRef > 0) {
			currentRadiusRefRef = -currentRadiusRefRef;
			sign = -1;
		}
		else {
			sign = 1;
		}
        }