V1 Board Enova Encoder error

[EVElvis]

Hi All
I have just joined this forum, having been regularly on the DIYev forum in the past. Pleased to see the progress and a forum for these great inverter developments. My project uses a V1 board and i have learned a great deal from its build which has benefitted my career, so thanks to Johannes and others that helped me along the way.
Its been nearly 3 years since I ran my project car and I am nearly back where I left off , but I have yet to get any smooth motor start.
Now that i have latest software, today whilst spinning the wheels with car on axle stands the motor still starts very roughly and I get ENCODER error. I have always suspected there was something going on with the encoder signal when i last ran it with old software, but put it down to interference somehow, but never investigated until today.
I have the 90kW Enova induction motor with optical HED-5605-F13 encoder with 256 pulses / revolution and I have taken 5V from the sensor board to power it. Signal to pin 3. I have read that the V1 board and R3 value can be altered to suit higher frequencies which this encoder will generate at > 2300 rpm, so I wonder if anyone has tried this? But since this is at motor start, as it gets spinning I do wonder if it is something else?
I know there is more experience with this motor now, so wonder if anyone else has found the same issues?
Cheers
Tim

[rikohm]

I got dust in the encoder wheel on my HEDS sensor, didn't show up on scope most of the time (hand turning) but generated a lot of errors at times while driving. See Substation1 in projects...

[tom3141]

Hi Tim.

You may remember we spoke a few years back regarding the Enova motors. I've been slowly progressing with my Suzuki Cappuccino conversion over the last few years and finally got it moving today. I also have some issues with the Enova (see the thread I've just started viewtopic.php?f=2&t=755). Not sure whether it's encoder related or not but it doesn't sound the same as your problem as mine will run really smoothly if I'm gentle with the throttle.

Tom

[EVElvis]

Hi Tom
Yes I recall we discussed the Enova stuff. Would be good to see your project, and pleased to hear you have got it driving. I have only just picked mine up again after nearly 3 years, apart form making a digital speedometer which relies on an encoder signal . I used the connection for this to connect my scope.
So heres a few videos from this morning:

First one shows in neutral what looks like a good encoder signal:
This shows what appears to be interference from PWM signals as I switch in and out of FWD/RVSE:
Then my attempt to spin wheels which shows poor signal, no doubt why the controls cannot sync the phases:

One thing I have not tried to change is PWM frequency, and I wonder if more than 4.4 kHz will make matters worse? In anycase need to understand what is going on.
The only other thing I did was disconnect shielding from motor housing as I saw Damien had done this. The shielding is now only connected at the inverter cooling plate. I also note that the motors 3 phase outlet is right beside the encoder input, and I know the shielding on the 3 phases was damaged on my unit, so I need to investigate that too.

[arber333]

You need to connect motor and inverter with a thicker grounding cable since usually motor is suspended by rubber shocks. I see sparks off motor and inverter when I ground them together, so there is quite some potential...

[EVElvis]

Good shout arber333, I had forgot to connect it. It is 25mm2 cable connecting motor and inverter (both already connected via bolts) to chassis. Just tried again though and seems no change unfortunately. I can barely get the wheels to turn
Im thinking that 3 years ago the difference was that I used the parameter encflt = 4 (an encoder signal filter in the software) on top of the hardware low pass? filter and it made a difference? 256 pulses per rev is rather high and I don't think helps? I can see that others are considering different encoders, so confident ill be driving again soon .

[johu]

Also read here: viewtopic.php?f=2&t=755

[EVElvis]

cheers Johannes, good timing to finally sort these Enova Hyundai motors.

[SciroccoEV]

I commented on Damien's video;

Back in the 90's we were using RS485 drivers at the encoder to transmit a noise tolerant signal.

[Jack Bauer]

Yeah I've been around this merrygo round a few times. The noise originates in the encoder not the lines. I'm adapting a cheap 100ppr encoder from ebay. We'll see how that goes. Something like this :
https://www.ebay.co.uk/itm/Incremental- ... 3324505416

[EVElvis]

Looking more like encoder is indeed the issue following a few extra tests that I wanted to do to eliminate an IGBT being broken which is something I have previously experienced.

- Manual mode with encoder disconnected - smooth start and rotations of motor achieved.
- Manual mode with encoder connected - not so smooth but was able to spin wheels (not sure if SW was using signal in manual mode?)
- Auto mode and all connected - not easy to get wheels to spin at all with everything connected

Im interested to know what has changed in the software which has made a difference - removal of encflt parameter that helped deal with the noise?

I'm adapting a cheap 100ppr encoder from ebay. We'll see how that goes. Something like this :

Look forward to see how you get on Damien, good luck!

[EVElvis]

Took the Avago encoder off last night and could see it was indeed 256 pulses on the disc, all evenly spaced.

Perhaps 256 pulses and the slop in the drivetrain (im using original single reduction gearbox off the Edison van) will causes more erratic pulse signals? So i have just ordered one of these to try:
https://www.ebay.co.uk/itm/AVAGO-Optisc ... 1438.l2649
Luckily postage was cheaper than advertised
Looks like I will have to adapt outer shell of old encoder to this one to mount it, but i hope 50 ppr will at least help highlight something? Enova clearly used two channels, which may have helped get it working for them?
Was interesting to see 4 unconnected wires into motor casing - they measured 320 kOhm accross them, so not sure what they are for?

[EVElvis]

I now have my optical 50 ppr encoder and i didnt get much of a change with single encoder mode, but the reactions of the set up seem less violent. I get loads of strange noises (like the old internet dial up noise i think) from the inverter when it tries to run the motor which still barely turns, unless i go into manual mode, so im now less convinced it is the encoder itself, but i can get some nice sounding ev inverter whine (like i used to get 3 years ago with v2.97? SW?) but somewhat pulsed wheels turning with AB encoder mode, so i dont know why this is so different to single mode, apart from the obvious pulsing probably because theres only one signal input?

Im going to focus on the switching of T1 next as I have only seen it switch cleanly turning the wheels by hand, so when powered I hope to see it switch ok. All good learning

[Jack Bauer]

Ripped out the original encoder today on the rear drive motor on the range rover and replaces with this thing from ebay. Very big improvement. Not perfect, but much better. Never thought I'd be thanking the clown who cut out the floor...

[johu]

Are these waterproof? I consider swapping the one in the Polo as it recently played up

[EVElvis]

I don't understand what is going on, but I can see what seems to be a poor signal from the encoder? I did get smooth running in both manual unlimited frequency it seems, but only up to 1 or 2 Hz run mode via pedal for some reason, but then i keyed off and on and i couldnt even get manual mode to work properly, so possible something else is going on, or i changed something in my haste to try different parameter values?

I used my scope channel 1 - top line encoder signal to T1 base.
Channel 2 lower line T1 emitter signal.

Manually turning wheels in neutral:

Manual mode 0 to 20Hz:

Attempt playing with udcnom values 0 , 50V (actual bus voltage), 300V (motor plate) until it trips with 300V set:

Another attempt with different parameters set:
(Channel 1 disconnected)

Im thinking about changing R3 & R4 to 500 Ohm resistors, but I doubt very much that's any cause for the problem.

Ripped out the original encoder today on the rear drive motor on the range rover and replaces with this thing from ebay. Very big improvement. Not perfect, but much better. Never thought I'd be thanking the clown who cut out the floor...

Thats great news Damien, think i will be looking for something similar.

cheers

[EVElvis]

Instead of the 5V from sensor board that i was using, I found that a separate 5V power supply has made a huge difference, and now i get the inverter to respond smoothly and the encoder signal is clear. I used a bench power supply first, and i have one of these https://www.ebay.co.uk/itm/12V-to-5V-Du ... 1976793008 and it works well too, so i will probably use it.
Now i need to get the wheels spinning faster than the 60 rpm or so I can get at the wheels with 50V test pack. Played with the parameters for a while but no great rpm improvement, so any ideas for parameters would be appreciated. Currently i have: boost 6000, fweak 121, fslipmin 1, fslipmax 2.7, ampmin 4, udcnom = 50, fmax 150, deadtime 63, idcmax & iacmax = 300. I think I have pot parameters wrong - dual channel, but both follow 0 -100 % throttle with values like 500 - 2500 min to max, so I guess pot 2 needs to be opposite max 500, min 2500? Cheers

[arber333]

At 100V you would need like 3x the normal boost. Try 15000 or 18000.

[EVElvis]

thanks arber. Unfortunately no luck with that, but it spins so I think boost is ok? I tried 18000 and it didn't go any quicker. Ive attached the parameters that I last tried, would greatly appreciate if those with more experience can have a look and spot any major reason why I cant get much more than about 60 rpm at the wheels. The last time I spun the motor quickly was 3 years ago on something like version 3 SW. Could it be that there is no load sensed as I have the wheels in the air? Im also using an old web interface.
cheers

[tom3141]

When I was running mine at 30V I had boost at 6000, fslipmin at 1, fslipmax at 2.8. Try setting fmin much lower, I think I had it at 0.05.

Other than that your settings look very similar to what I used for running at 30V.

I’ve got some updates on my testing with the encoder that I’ll post later when I get a chance.

[tom3141]

Out of interest, what happens at 60rpm? Does it seem like it’s hit a limit? Any noises from the motor?

[EVElvis]

Thanks Tom
Ive not measured rpm, but I rekon its 60 rpm at the wheels and yes it seems to be the limit, which is going to be around 500 rpm for the motor.
No noise that I have noticed. The inverter seems to be very smooth, and I hardly get any whine now either, not sure if that's good or not?
I have tried fmin around 0.06, but that's a good shout as I have had it up just less than fslipmin for my last efforts.

[EVElvis]

Just tried fmin 0.05 and as much as I could think of changing that may influence the low rpm at full throttle.
I have no idea what is going on, and I have had parameters set the same as 3 years ago when it all ran rather well Theres only the odd parameter not showing now like encflt, and a load of new ones with the latest SW. Tempted to put old SW back on, but im reluctant given the improvements which protect the hardware better.

[arber333]

OK first you want to change "deadtime": "63", to something higher. I advise this to all. I didnt see which inverter you use and which drivers, but i would advise you set this at least 85 or even 180.

Is your motor really 4 pole? Is it possible it would be 6 pole?

If not that, can you use another inverter and/or different ACIM motor with this configuration?

Also i see you are using a Rev1 board. So you have single channel encoder interface. There is no AB signals in Rev1 board. Just channel A through transistor. The other pin provides 5V to encoder. Maybe you want to change thransistor type?

Can you rotate motor in manual mode? Remember this is V/Hz. So you provide 80% ampnom and 1Hz fslipspnt. When it starts to spin you add more fslipspnt. 3Hz, then 5Hz then 10Hz and 20Hz and 30Hz.... 50Hz, 70Hz...100Hz etc... Main point of this excercise is you will run out of voltage at some point ant you then read the speed from interface.
Now run it in encoder mode and read speed as the motor rotates.
You may want to use more voltage...

[tom3141]

Have you checked the encoder signal with a scope as it approaches the problem speed?

I found the ‘on’ time was getting smaller and smaller compared to the ‘off’ time as the speed increased. The on and off pulses are not equal. Not sure if that makes sense but here’s a photo:

The width of the ‘off’ pulse is correct, the ‘on’ pulse becomes almost non existent at the speed that I get stuck at. It seems that this is what is causing my issue but I’m not sure of the root cause. Wondering if the encoder is not up to the job but if you have the same problem that would be very interesting.

As you can see I also have a lot of noise. This is on the 5V supply and the 12V whenever the forward or reverse is selected. Doesn’t seem good but I’m not sure if it’s causing the problem. The noise is present at all speeds so seems to cope with it ok. I did try adding a low pass filter on the 5V supply but that didn’t fix the problem. I didn’t have a scope at that point to check if the noise had been reduced though.

I also tried a separate 5V supply as you did but it made no difference for me. In fact it made it worse - I got clunking from the motor at lower speeds that work fine with the 5V supply from the board.