ZombieVerter precharge relay stays on

[mattes]

Have ZombieVerter setup on my test bench going to the various modes of operation.
Simulating the HV batterie using an adjustable power supply. Have an IVT shunt connected [Can2], reading the incoming high voltage.

case A:
- UDC parameter is set to 58V.
- power supply is set to 56V

enabling T15 and pushing start, I see the PRECHARGE relay being activated. Now i turn the PS knob slowly to 60V.
At around 58V, I see the MAIN relay coming on.
Suprised to see the PreCharge relay staying on, it never turn off.
Shouldn't it go off once UDC is reached?

case B:
- UDC parameter is set to 58V.
- power supply is set to 59V

enabling T15 and pressing start, I see the MAIN relay being activated immediately. It seems that PRECHARGE never turns on, which makes sense, since
the defined 58V is already is achieved.

Is case (A) a bug? Should the PRECHARGE relay turn off?
Might this be the reason why Damien blew a contactor is his Mitsubishi L200 build?



video clip:
[media]https://mykmk.com/zomby/zombiePrecharge.mp4[/media]

[tom91]

Yes the precharge stays on.

[peakPWR]

Yes the precharge stays on.

But why?

[tom91]

But why?

This is the way its coded, same in OI firmware. Believe its done to allow some back flow of power when the main relay gets dumped under fault conditions.

It is not usual practice in an EV, so can be removed at some point. Needs a bit of rework anyway.

[peakPWR]

It is not usual practice in an EV, so can be removed at some point. Needs a bit of rework anyway.

by adding something like

Code: Select all

DigIo::prec_out.Clear();

to MOD_RUN?

Code: Select all

    case MOD_RUN:
    	
        if(rlyDly!=0) rlyDly--;//here we are going to pause before energising precharge to prevent too many contactors pulling amps at the same time
        if(rlyDly==0)
        {
            DigIo::prec_out.Clear();
            DigIo::dcsw_out.Set();
            DigIo::inv_out.Set();//inverter power on
        }
        Param::SetInt(Param::opmode, MOD_RUN);
        ErrorMessage::UnpostAll();
        if(!selectedVehicle->Ready())
        {
            opmode = MOD_OFF;
            rlyDly=250;//Recharge sequence timer for delayed shutdown
        }
        Param::SetInt(Param::opmode, opmode);
        break;
    }

[tom91]

Sure that would do it.