Prius gen3 buck/boost [SOLVED]

[hox]

I need some help with getting the buck/boost converter on the Prius gen3 inverter to work using OI board (Damien V2). I have never been able to get the buck/boost converter to work despite reading the wiki, forums and watching videos.

My target is to get the module to boost 24v to 48v to drive a brushless AC compressor and also use it to boost DC from my solar array at 120v 8Kw to 380v DC to charge my pack.

What I have tried;

PWMing the boost HI drive while pulling the LO drive to ground and sending DC from either direction without any buck or boost activity. I also tried pwming the LO drive line while pulling the HI line to ground but still no response.

I have tried using the onboard uno and also using a signal generator to drive the inputs.

Can someone help with what I am doing wrong?

[MattsAwesomeStuff]

[Edited] - Err, ignore me. You said buck/boost, not DC-DC.

[wasted of time]You probably know this, but the Gen 2 has 1-wire activation. It has other wires to control it a bit, but, you can get it working and doing its normal thing with just one wire.

On the Gen 3... does this thread help?:

viewtopic.php?f=14&t=1039[/ignore]

[hox]

It’s okay Matts.

Yh I mean buck/boost. It’s doing my head in unable to get it to run. It appears the high side is always turned on by default as powering through the battery bus shows input voltage on the DC bus, should that be happening or do I have a short on my IGBT?

[jrbe]

I have experience with gen 2, I think it's similar.
viewtopic.php?p=79368&hilit=Dc+dc+converter#p79368

You have to have pwm running before turning on the 2 enable lines (one high, one low) or the ight will be high or low depending on what you setup the pwm line with for a pull up / down resistor when enabled.

There are also 12v signals (not 5v or 3.3v) for these inputs. If I remember right they switch over around 7v.

Watch out for turn off spikes if there's no beefy load on it. I ended up watching for brownout and shut the enable lines off when shutdown or brownout is sensed.

I also thought it could buck or boost with the in / out wires fixed in place. This isn't the case. One physical side of the converter is low side, the other is high. So you get a ratio of .2-100% or 100% - 2000%? (but igbt limited voltage of course) depending on which way you feed power in and what the duty cycle is.

[hox]

Thank you @jrbe, I finally found the first error which was from the pin assignment on the boost converter code in the wiki not the same layout as the uno on my board. I have now corrected the pin assignment now and seeing the IO pin being driven high/lo for the drive lines.

However, doing a ground continuity test on my multimeter gives a constant tone when i check the collector pin of the TR9 transistor for the HIGH line when the 50way connector is disconnected and gives a flickering tone when connected.

Any further pointers?

[jrbe]

The 12v- and the high voltage - are not connected.
Don't share the high voltage - with the low voltage controls -.
Make sure your uno and the 12v grounds are connected.

Make sure you are driving all the controls lines on the high side high enough. What voltage is high in your controls setup?

Be aware this is NOT an isolated DC-DC. The ground between high and low sides are shared.

[hox]

The Uno is driving a non transistor which is pulling the boost hi line on the 50way connector to ground.

The high voltage from the uno is 4.7v which passes through a 1K resistor connected to the base of the transistor (MMBT3904).

The boost Hi line from the 50way connector is connected to the collector of the transistor with emitter to ground.

Turning on the transistor pulls the boost Hi pin to ground. Is this correct?

[jrbe]

When you say uno do you mean the Atmel section of an OI / Damien PC board or an uno you setup? Can you share an image of your setup?

...Edit...
What voltage swing do you see on the igbt controls pins when toggling them high / low? If this is only 4.7v this is your issue. An uno will only run at ~5v, I don't mean to power the uno 5v line with 12v...
The uno / Atmel drives transistor gatess pull ups / downs to make the 12v signals the igbt needs.
The igbt gets 12v too.

[hox]

Sorry I’m mobile right now

Yes, Atmel of Damien board, the V2 for Prius gen 3. I am not close to it to get a picture right now.

I mean I am seeing 4.7v coming from the Uno IO pin going to the base of the transistor which is pulling the boost HI line to ground.

Seeing how the pwm transistors are driven in a similar manner, I think the Uno is driving the booster transistors now or what do you think?

[hox]

It is working now, for some reason the 12v power supply was being pulled to 5V and I didn’t realize it.

I replaced the power supply and all is well now. Thanks Jrbe and Matts