BMW I3 REX Inverter REME Issues

[sdobbie]

Hi everyone, I have resumed work on reverse engineering the small inverter for the BMW I3 to create a vesc based drop in board for it. The drop in board provides all the power supplies the powerstage module requires.

The strange issue is that the motor is very difficult to turn when the drop in board is switched on with no hv supply attached to the 3 half bridges.
With the drop in board disconnected entirely and the hv supply to the half bridges switched on, the motor is difficult to turn.
The only way the motor will spin freely by hand is when no power is applied to the powerstage or the drop in board.

The powerstage will not respond to PWM inputs, when the vesc board supplies any PWM signal, I get a single tick noise from the powerstage and nothing happens. The gate driver fault output goes low when this tick happens, indicating a desaturation event.

I have tried manually pulling all 3 gate drive inputs for the low side IGBT's high and low, and nothing happens. I then did the same for the high side IGBT inputs with nothing happening.

I'm totally stuck on this one.

[Ingineer]

Hi, Just found this! I'm interesting in participating on this hack, I'm considering using an i3 Rex for another project. My intial idea was just to get a CAN log from a working i3 that includes Rex startup, run, charge, and shutdown. With this it would be possible to just control the REME with the existing Tri-core, but even if this is too limited, it's a good starting point to be able to gather drive waveforms.