openinverter forum

Dan--T wrote: ↑Thu Nov 19, 2020 3:32 pm Thank you!

Very clear, and the Wiki is extremely useful, sorry should have re-checked that!

Dan--T wrote: ↑Sat Nov 21, 2020 12:18 pm Thanks yes I'm going to go through it all in detail now, got a lot of learning to do!

Just placed my order for a V2 kit, so looking forward to getting things moving in the new year!

Robbertjanzen wrote: ↑Sun Apr 05, 2020 9:51 am To make it more clear, i have made a complete wiring diagram for the V2 board in visio.

As i am also missing the original wiring loom, unfortunately i can not check if all connections are correct.

I would really appreciate if everybody gives there remarks so i can modify and finalize the drawing.

Please also find the Visio file here:
https://www.dropbox.com/s/e42971nsftjav ... .vsdx?dl=0

xp677 wrote: ↑Thu Feb 20, 2020 12:50 am It's glued/bonded in - I had to smash mine out. I think I used a screwdriver and then a craft knife to clean up the rest. Be careful not to cut yourself or scratch the aluminium, it's a mating face for my cover!

DC bus cover pictured in my last post is done. I just want to add o-ring grooves around the cable entries, and a million other tiny things that I'll notice.




Now onto the converter input cover!

Dilbert wrote: ↑Wed Dec 16, 2020 5:07 pm

xp677 wrote: ↑Thu Feb 20, 2020 12:50 am It's glued/bonded in - I had to smash mine out. I think I used a screwdriver and then a craft knife to clean up the rest. Be careful not to cut yourself or scratch the aluminium, it's a mating face for my cover!

DC bus cover pictured in my last post is done. I just want to add o-ring grooves around the cable entries, and a million other tiny things that I'll notice.




Now onto the converter input cover!

Does anyone have a Step/Iges/SLDPRT file for the GS450H inverter that they are willing to share? I've access to a 3D printer at the moment, so i would like to print one.

bobbyj_408 wrote: ↑Thu Dec 17, 2020 1:51 am So I want to make sure I understand the precharge logic in the VCU. When the inverter is precharging, the inverter will report back the dc bus voltage. As the voltage is increasing, that will get read in to the VCU. Once it has reached a threshold, it will close the main contactor. In essense, the inverter is the one sensing the voltage, the VCU receives that value, and controls the contractor.

On top of that, I notice that the threshold value is hard coded to 400. What if my battery isn't at 400V? I'm using a Chevy Volt pack and I believe it's nominally at 350V. What that also means is that when it's low on a charge, it can be quite a bit lower than 350V, and when it's on a full chaege it can be higher than 350V. How can we compensate for this? Would the idea be to set the threshold very low? If I do that, and the pack is full, wouldn't that cause a current rush?

xp677 wrote: ↑Wed Dec 23, 2020 4:10 pm
Ideally you want to compare the reading from the inverter with the reported pack voltage from the BMS. So that as the battery pack voltage decreases, your expected dc bus voltage changes accordingly.

For your system, it might be an idea to grab the pack voltage, and set the threshold based on this during startup.

For my system, I sum all the cell voltages to get the pack voltage, and my conditions to close the main contactor during precharge are:

1. inverter DC bus voltage is within x of the pack voltage
2. current through the battery pack's current transformer is less than y
3. more than z milliseconds has passed.

I don't have the values to hand, but it's probably something like 10V difference less than 5A, and 1 second passed.

I know that Damien and others recommend a voltage/current sensor which could be useful for this as well.

From experience, the inverter's readout is not especially accurate.

The point of precharge is to prevent an inrush when applying pack voltage to the DC bus capacitor within the inverter. In reality, measuring the current flow into the inverter is a more direct way to handle this.