openinverter forum

Hi!

I spent the summer converting a Volvo c202 Laplander to electric drive. It will be used on a small island, mainly for handling boats and doing work in the forest.

It’s up and running with the em57 connected directly to the Volvo gearbox, no clutch. After the gearbox there is a transfer case that enables 2 or 4wd as well as high/low.

Everything works fine but I have issues in low speed range, the car tends to oscillate at very low rpm, it’s like it’s stuck between regen and actual driving. This makes is hard to tow a boat on a trailer and other things that requires precision.


As soon as I go over 10-15kmh it’s smooth, even when the throttle is released.

I played around with regen and it made some difference but I need it to be smoother on low rpm.


Any ideas?

Provide more setup info, what controller you running?

Provide parameter .json.

{
"iqkp": 60,
"idkp": 32,
"curki": 20000,
"vlimflt": 11,
"vlimmargin": 2500,
"fwcurmax": 0,
"syncofs": 1000,
"lqminusld": 0.59,
"fluxlinkage": 90,
"syncadv": 10,
"polepairs": 4,
"respolepairs": 4,
"sincosofs": 2048,
"encmode": 4,
"fmax": 200,
"numimp": 400,
"dirchrpm": 100,
"dirmode": 1,
"snsm": 14,
"pwmfrq": 1,
"pwmpol": 1,
"deadtime": 78,
"ocurlim": 500,
"il1gain": 2.31,
"il2gain": 2.31,
"udcgain": 5.21,
"udcofs": 250,
"udclim": 540,
"snshs": 6,
"pinswap": 6,
"modmax": 37836,
"potmin": 475,
"potmax": 3130,
"pot2min": 231,
"pot2max": 1590,
"potmode": 1,
"throtramp": 2,
"throtramprpm": 20000,
"throtcur": 3.5,
"brakeregen": 0,
"regenramp": 1,
"regentravel": 5,
"offthrotregen": -10,
"cruiseregen": -20,
"regenrampstr": 25,
"brklightout": -50,
"bmslimhigh": 50,
"bmslimlow": -1,
"udcmin": 160,
"udcmax": 200,
"idcmax": 500,
"idcmin": -200,
"idckp": 2,
"idcflt": 9,
"tmphsmax": 100,
"tmpmmax": 150,
"throtmax": 100,
"throtmin": -100,
"accelmax": 1000,
"accelflt": 3,
"chargemode": 0,
"chargecur": 0,
"chargekp": 80,
"chargeki": 10,
"chargeflt": 8,
"chargepwmin": 0,
"chargepwmax": 83.5,
"idlespeed": -100,
"idlethrotlim": 50,
"idlemode": 3,
"holdkp": -0.25,
"speedkp": 0.18,
"speedflt": 5,
"cruisemode": 0,
"cruisethrotlim": 50,
"udcsw": 160,
"udcswbuck": 540,
"tripmode": 0,
"bootprec": 0,
"pwmfunc": 0,
"pwmgain": 100,
"pwmofs": 0,
"canspeed": 1,
"canperiod": 1,
"nodeid": 1,
"controlid": 63,
"controlcheck": 1,
"manualstart": 0,
"manualiq": 0,
"manualid": 0
}

version 5.32.R-foc
hwver Rev3

Try decreasing curki, say 10000 or less and check if it helps.
Idkp seems low, increase to about 100

I will try it tomorrow.

Did a test earlier today were I connected a 500Kg trailer to the car and it mas much smoother on low rpm's with the load attached. Dont know if this changes your recommendation.

Thank you!

R

This config works like a charm!

{
"iqkp": 60,
"idkp": 100,
"curki": 4000,
"vlimflt": 11,
"vlimmargin": 2500,
"fwcurmax": 0,
"syncofs": 1000,
"lqminusld": 0.59,
"fluxlinkage": 90,
"syncadv": 10,
"polepairs": 4,
"respolepairs": 4,
"sincosofs": 2048,
"encmode": 4,
"fmax": 200,
"numimp": 400,
"dirchrpm": 100,
"dirmode": 1,
"snsm": 14,
"pwmfrq": 1,
"pwmpol": 1,
"deadtime": 78,
"ocurlim": 500,
"il1gain": 2.31,
"il2gain": 2.31,
"udcgain": 5.21,
"udcofs": 250,
"udclim": 540,
"snshs": 6,
"pinswap": 6,
"modmax": 37836,
"potmin": 475,
"potmax": 3130,
"pot2min": 231,
"pot2max": 1590,
"potmode": 1,
"throtramp": 2,
"throtramprpm": 20000,
"throtcur": 3.5,
"brakeregen": 0,
"regenramp": 1,
"regentravel": 15,
"offthrotregen": -20,
"cruiseregen": -20,
"regenrampstr": 25,
"brklightout": -50,
"bmslimhigh": 50,
"bmslimlow": -1,
"udcmin": 160,
"udcmax": 200,
"idcmax": 500,
"idcmin": -200,
"idckp": 2,
"idcflt": 9,
"tmphsmax": 100,
"tmpmmax": 150,
"throtmax": 100,
"throtmin": -100,
"accelmax": 1000,
"accelflt": 3,
"chargemode": 0,
"chargecur": 0,
"chargekp": 80,
"chargeki": 10,
"chargeflt": 8,
"chargepwmin": 0,
"chargepwmax": 83.5,
"idlespeed": -100,
"idlethrotlim": 50,
"idlemode": 3,
"holdkp": -0.25,
"speedkp": 0.18,
"speedflt": 5,
"cruisemode": 0,
"cruisethrotlim": 50,
"udcsw": 160,
"udcswbuck": 540,
"tripmode": 0,
"bootprec": 0,
"pwmfunc": 0,
"pwmgain": 100,
"pwmofs": 0,
"canspeed": 1,
"canperiod": 1,
"nodeid": 1,
"controlid": 63,
"controlcheck": 1,
"manualstart": 0,
"manualiq": 0,
"manualid": 0
}

Does it behave differently in fwd vs rev?

Zieg wrote: ↑Thu Aug 22, 2024 6:51 pm Does it behave differently in fwd vs rev?

No, but there is a difference between high and low because of the big difference in gear ratio. The c202 has two gearboxes. The first one is has 4 gears + rev. The second one has high and low and also controls the 2-4wd.