openinverter forum

I also got the DC-DC working happily with 350v of rectified AC on the HV bus. So seems the DC-DC has a pretty wide operating range at least.

Is the Ohm level of the resistor for CPWM specific? Or will 470 Ohms suffice?

My wiring and the sequence matches, only CSDN is left floating and not connected to ground. I will try to bypass the resistor on the CSDN line, since that is the only difference right now.

Do you have to activate buck mode on the web interface or is fwd and rev signals enough to do that?

You have to select one of the two charge modes (and save that!). I found 500 Ohm to be sufficient pull-up, 1k2 was already too much. 470 will work as well

Ah I never did save the setting, always changed it once the inverter was running. I'll try that Tuesday evening when I am there next.

Johu and LRBen, am I understanding that the initial setup (attachement in first post) , is still the same, except instead of charging via Mg1, we will link to AC output?
Or is Johu developing the AC version, and LRBen continuing the Mg1 version?

I am continuing down the mg1 route for now. From what I can tell the only difference in setup is where the mains AC wires go into the inverter and you set it to boost instead of buck when going through the Air con
Plus the physical changes Johu has done to the Air con part.

Ok, thats what I plan until Johu has cracked the AC option.
So yes, Setting to BOOST and saving in parameters is the firts step (will update the sequence in first post)

Revised wiring diagram on first post. Now to implement.

RetroZero wrote: ↑Mon Mar 21, 2022 9:43 am Ok, thats what I plan until Johu has cracked the AC option.
So yes, Setting to BOOST and saving in parameters is the firts step (will update the sequence in first post)

Set to Boost if you are going through Air con, Buck if you are going through MG1.

Oops, hit that wrong way round. Buck it is for Mg1.
Do you keep the AC precharge pulled to GND as in the diagram I made? I don't see it's relevance.

Here is my current setup.

Sorry, first I connected HV battery to DC-DC converter

I don't actually use the triple-pole relay for switching 230V AC since it is too weak, but I enable a second relay. But for simplification I omitted that

Triple pole relay also activates DC-DC converter during charging and driving

Had another go tonight and I think it is working. I can get variable voltage outputs on the battery connection with the heater element working.
Still get the EVSE cutting out. Which you can hear in the first video more, as it cuts out the inverter also cuts out.




The second videos shows varying voltages on the battery connection


I think I just need to stop the EVSE from freaking out and it should be fine.

For tests set chargekp=0. That's what mine sounded like with the default of 80.

Sounds good, I'll try with that on Thursday and see what happens.

Nice going on the 2 options.

I've bypassed EVSE and it seems quite stable now.

I think I might need to look at current and voltage calibration as it doesn't match up too well right now. But voltage does move with pwm min and max.

The graph is looking a bit irregular as well/
Edit:
Current draw from the mains seems to stay constant at 2.7Amps. This doesn't change with charge amps, even though there is a noticeable difference in the heating element.

I noticed I need to put in some diodes as per Johu's diagram before wiring up. Thanks for pushing on.

Any suggestions for threshold limits before I order some?

LRBen wrote: ↑Thu Mar 24, 2022 3:56 pm The graph is looking a bit irregular as well/

There's almost no capacity in the system, so basically your battery current is sinusoidal, of course with the negative flipped to the positive. Regular chargers have a lot of elcaps and a PFC stage to be able to supply smooth DC. To my knowledge batteries don't mind being charged that way though.

johu wrote: ↑Thu Mar 24, 2022 7:26 pm

LRBen wrote: ↑Thu Mar 24, 2022 3:56 pm The graph is looking a bit irregular as well/

There's almost no capacity in the system, so basically your battery current is sinusoidal, of course with the negative flipped to the positive. Regular chargers have a lot of elcaps and a PFC stage to be able to supply smooth DC. To my knowledge batteries don't mind being charged that way though.

I did read an article somewhere that said pulse charging can result in the battery taking more charge than smooth CCCV. I was more worried that the peaks are not that regular.

I also had a thought while driving home, I don't actually need any bucking since my 80s cells needs 336v to be fully charged. I'm getting 325v on the HV bus which is 80/85% SoC ish. Can I just charge the battery from the HV bus connections and skip any bucking or boosting stages? I'm assuming I would lose current control, but with a granny charger that's no big deal.

Don't even think about it When your battery is discharged it will be way below rectified AC -> immediate braker trip

Glad I asked on here first! In that case I just need to set chargepwmmax to 99(with chargepwmmin at battery discharge voltage) which has the same end result.

So I decided to add in the OI BMS and Isa shunt into the test setup. Wanted to check for current from the ISA shunt canbus so ran the charge process through the type 2 connector and EVSE which I had wired back up. Ran perfectly, EVSe was happy. Isa shunt read a steady -2.9 amps.

No idea what changed. Perhaps I just had something not quite connected right the first time around. Will test more with real batteries next week as now I have my steel compression pieces.

Hello. I want to clarify for myself in order to dispel doubts about the simultaneous use of one inverter for driving and charging in the parking lot. Does someone use such a combination of functions for the prius Gen2 inverter?

alehandro wrote: ↑Tue Mar 29, 2022 6:36 pm Hello. I want to clarify for myself in order to dispel doubts about the simultaneous use of one inverter for driving and charging in the parking lot. Does someone use such a combination of functions for the prius Gen2 inverter?

Yes that how Johu and myself are both using it. We are just connecting the AC in different places in order to buck or boost the rectified AC.

In terms of battery connections, ground is the same but you will need two positive contactors, one that connected to the main HV bus for driving and another to connect to the default battery positive input for charging. Then make sure you close the correct contactor when you are driving or charging.

LRBen wrote: ↑Tue Mar 29, 2022 8:02 pm

alehandro wrote: ↑Tue Mar 29, 2022 6:36 pm Hello. I want to clarify for myself in order to dispel doubts about the simultaneous use of one inverter for driving and charging in the parking lot. Does someone use such a combination of functions for the prius Gen2 inverter?

Yes that how Johu and myself are both using it. We are just connecting the AC in different places in order to buck or boost the rectified AC.

In terms of battery connections, ground is the same but you will need two positive contactors, one that connected to the main HV bus for driving and another to connect to the default battery positive input for charging. Then make sure you close the correct contactor when you are driving or charging.

If I understood correctly, is there a connection diagram in the first post of the topic? Could you please share the correct detailed switching scheme for the two modes "drive" and "charge"?

I'm working on the diagram in the first post today . Will update if successful. Note, there are 2 versions, I am using the Mg1 option in this diagram (Johu has a AC compressor output version)