[Qer]

Originally Posted by piotrsko

I suppose those are the hazards of writing code while the EE is still building the hardware. Perhaps too much onioins?

Na, the hardware is finished since a while ago but I've been lagging behind a bit lately since I have a daytime job too. Version 1.0 of the software is pretty much just running the controller with basic functionality, version 1.1, 1.2 and so on will be improvements and feature creeping. I have a looooooong wish list.

[280z1975]

Originally Posted by Qer

snip ... version 1.1, 1.2 and so on will be improvements and feature creeping. I have a looooooong wish list.

I do like the sounds of that ... features, wonderful features

[Qer]

Yes, we're still alive. Yes, we're still working on the controller. Yes, things are still being improved. Today Tesseract and Seb tried out a new feature, power limit!



What you see here is an example of Tesseracts sense of humour. When Seb let go of the throttle (at about 462) Tesseract reduced maximum power to 20 kW which meant that Seb suddenly were driving a snail. Then, at around 513 or so, Tesseract restored power while throttle were still engaged! maniac!

(note: I don't recommend messing with the parameters while the controller's running, but they were, after all, testing things and thus have my forgiveness)

So this is how the different limitations for the motor corresponds.



There's of course RPM-limit too, but that didn't really fit into the graph...

The reason for "chipping off" a corner of the power cube is of course that high voltage AND high current is very stressful for the motor, thus this little feature has been on my todo list for a while and since I've added an output setting for a power meter on the dashboard it kinda made sense to add a power limit so the meter knows what range it should use for 0-100%.

I guess I should start looking at SoC too now...

...or perhaps I should sleep. It's midnight in Sweden right now...

[TheSGC]

Originally Posted by Qer

What you see here is an example of Tesseracts sense of humour. When Seb let go of the throttle (at about 462) Tesseract reduced maximum power to 20 kW which meant that Seb suddenly were driving a snail.

Haha a snail. My EV gets 20 KW power for the first 5 seconds, then its down to under 12 KW after that. Good on battery life, awful for practical driving.

I don't know what sounds like more fun, adjusting the parameters while driving or having someone else adjust it and the driver have no idea what's coming.

[Qer]

Originally Posted by TheSGC

Haha a snail. My EV gets 20 KW power for the first 5 seconds, then its down to under 12 KW after that.

My condolences.

Originally Posted by TheSGC

I don't know what sounds like more fun, adjusting the parameters while driving or having someone else adjust it and the driver have no idea what's coming.

As I said, I don't recommend it. Since it's software there's always a risk it contain bugs and there's simply too many parameters that can be changed in too many ways for us to be able to test it thoroughly.

[major]

Originally Posted by Qer

Hi Qer,

The kW (red) line is a bit confusing. It looks like it is a 100 kW curve. And the only time you'd get that 100 kW is when you're at max demand between about 450 and 800 amps. Is that correct?

Regards,

major

[Qer]

Originally Posted by major

The kW (red) line is a bit confusing. It looks like it is a 100 kW curve. And the only time you'd get that 100 kW is when you're at max demand between about 450 and 800 amps. Is that correct?

Yep. Or whatever kW you punch in. For a daily commuter this might not be the number one favourite option in the web interface but for a high volt application you might like to be able to limit kW since you could theoretically peak over 300 kW with the Soliton1, which I personally guess would completely toast any DC motor fit for EVs. On the other hand you probably want to be able to get 1000 Amps at low RPMs OR as much voltage as the motor handles to get good top speed, just not at the same time...

Thus, kW-limit! Tadaaa!

[Qer]

Todays experience; a small software error in a test version (no worries, that particular version hasn't left the shop so no risk for any Soliton out there) resulted in a unintentional test of the hardware protection.

We're still messing with the idle code and found out the hard way that PWM width at some rare occasions could turn negative, which wrapped around to maximum integer value or, in "human terms", 100% pulse width. What that means is that the motor got full pack voltage while standing still which, of course, made current go ballistic. THANKFULLY Tesseract doesn't quite trust software (which is ok since I don't fully trust hardware ) so there's a built in hardware protection for over current that kicked in which cuts the power to the IGBT's and signal back to the micro controller which then cuts power too and drop the contactors (and that part of the code actually worked...).

The good thing is that the protection worked flawlessly and the controller in question still works fine (and a software version later idle does too). We've kinda dreaded doing that short circuit test (it's not that fun to short circuit a battery pack) so I guess it's a good thing that the software ended up testing it for us by mistake...

The bug is properly disposed of and there's also a new safety catch for negative pulse widths that now gets caught (yes, we tested before fixing the actual bug in question) before things go suicidal.

Sometimes life get's a tad too exciting...