Regen not working above 5mph [SOLVED]

[catphish]

I have an SDU running openinverter revision ce8c1e55fb91cd928c4b5ad4ccc56940596640ee - parameters attached.

For some reason I cannot get regen to work except in a very small band at around 5mph. If I set offthrotregen to -30, it seems that potnom is set to -30 as expected when the throttle is released, but there simply isn't any noticeable regen at speeds above 5mph. If i allow the vehicle to slow down naturally, I feel absolutely no regen until the vehicle slows to 5mph, at which point I feel very sudden and very noticeable braking, which brings the vehicle to a near stop.

This suggests to me that regen is absolutely working, but something is inhibiting it at higher speeds. I can't find any obvious explanation in the source code, but I'm wondering if it could be a bug as this version with hill hold has not been released and widely tested yet.

Tomorrow I will repeat this test and obtain a detailed log of the DC current, speed, and potnom. If possible, I will also add fslipspnt and ampnom to my logging.

[catphish]

Just went for a drive to gather the data, and it seems I'm somewhat incorrect about the symptoms. I *do* have regen at high speeds, it's just negligable, and then at 5mph something unpleasant happens...

Here's a graph showing a 0 to 60 to 0 run. It shows that I'm getting around 22A of DC regen current, but as the speed drops (to around 25Hz maybe) there is a huge spike in AC current, which seems to exist only between the inverter and the motor.

I assume the solution here is simply to increase the value of regenrampstr to eliminate that current spike, however I am puzzled as to why the regen is so little. At a potnom of -30 I'd expect it to be quite a bit more noticeable.

fslippnt is -2 as it should be, and unfortunately I messed up the command to log ampnom, so I don't know what it was doing throughout.

drive3.png

I will do another run shortly with offthrotregen increased to -40 and regenrampstr increased to 25. Hopefully this combo will result in noticeable regen without the low frequency current spike.

[catphish]

Fixed. Raising regenrampstr to 40 eliminates the current (and braking) spike at low speed. Increasing offthrotregen to -40 creates a meaningful amount of regen braking (-37A) at all speeds. Interestingly

drive4.png

It doesn't seem to be possible to map ampnom to CAN, at least not at the same time as fslipspnt. Each time I try, it appears to work, but then I end up with fslipspnt mapped twice.

In any case, marking this as resolved, hopefully it helps anyone else with the same misconfiguration!

[johu]

Yes CAN mapping of these is dodgy. They both have uid=0 as I don't want them stored to flash and that makes it impossible to recover CAN mapping