KLS-S controller issue : rev limited ?

Fardenco

10 µW
Joined
Dec 6, 2019
Messages
6
Hi guys, I'm currently on the project of building my first electric vehicle, but I have a problem with the controller (I guess).
Everything works great at low speed, but at around 1800 to 2000rpm, the motor speed drops down quite brutally, then goes up, drops down again, etc., like you would see on a gas engine with the rev limiter.
Please have a look at this video : https://mega.nz/#!9FZgkSBQ!2We1l1p6rBtGSsu_U67SMiofROuMwd8b8ypjRHWuvnY
I've checked the max speed settings, it's supposed to be 6000rpm, and with the motor I have, the controller could even be able to reach 12.000rpm.
It doesn't look like a software limit to me, because I tried to put the limit at 1000rpm to see what happens, and I found that the motor revs up quickly (because there's no load) but comes down gently to 1000, everything is smooth, not like in the video.
Here you can find screenshots of the settings :
https://mega.nz/#!pBIGQKYb!ghLHdVJaVcSg3sCl4_zu3c3XALBztJSjlWYTKktqOA0
https://mega.nz/#!kRQSxIZT!e6iUN082oiMjkxajehYRMN_3VYjl8oQD4UkygMOgnSs
The controller is a KLS6025S, and I don't know the ref of the motor but I know it's a 6 pole pairs BLDC motor.
Do you have any idea of what could cause that ?
 
It's a sensored brushless motor, 6 pole pairs, inrunner. I don't know much more because I don't know its reference.
The erpm limit of the controller should be 70.000rpm, that's what the manual tells us.
The motor has 6 pole pairs, so at 2000rpm that's 12.000erpm, right ? Much bellow the maximum of the controller so I don't think that's the problem, but maybe I'm wrong
 
There are more setting screens, please show all, especially the ones with speed limits and the basic settings.
Did you perform auto-identify succesfully?
Do you drive the halls with 12V or 5V?

The sound from the motor was strange, what is it? hub motor, mid drive or something not ebike related?
- Please upload a picture of the motor and all markings.

Does motor and controller work the same way as in video when loaded? sometimes the kelly program can loose sync unloaded.

-What kind of throttle do you have? Is it a hall sensor throttle?

-What throttle limits have you set?
 
Hi,
I'm sorry, I did not see your message.
Here are the screenshots :
Vehicle : https://mega.nz/#!JRhgEKrQ!TdqAN1UNQCbUg6C-i2pGeOEYZzS2Yh9ve3wSWEZFnNs
Motor : https://mega.nz/#!pBIGQKYb!ghLHdVJaVcSg3sCl4_zu3c3XALBztJSjlWYTKktqOA0
Control : https://mega.nz/#!kRQSxIZT!e6iUN082oiMjkxajehYRMN_3VYjl8oQD4UkygMOgnSs
The hall sensors are powered by 5V from factory, but I tried to power them with 12V, nothing changed.
Here is a picture of the motor : https://mega.nz/#!EIRU0KCR!DAkSdYZBeYNeULBlauOggMGhftQNEc9ItXFzq-C2nos
Here is the motor opened : https://mega.nz/#!FRJw0S4b!JIq8fBK9l-SzaqVYdzYl42d2yJHYo1DPoO6K0G26YA0
Unfortunately, I could not find any marking anywhere on the motor.

I will try with the wheel and chain attached. Do you think that would be a sufficient load ?
The throttle is a potentiometer inside a handle, like this one : https://www.amazon.com/dp/B07VJWX9ZD

I tried various settings for the throttle limit, but I think that's the problem because on the monitoring screen, the one you see on the video, the "TPS Pedal" value stays stable at around 200 when the problem happens, but I might be wrong

Anyway thank you for your time !
 
Think i’ve seen this issue before on ES. From memory that time the recommendation was to use kelly kbs controller since motor back emf is square shaped.
Motor might be poor match for sine controller.

What is your battery voltage and what is motor kV?
Do you get any errors at all in program?
Have you changed PID parameters from default?
 
Think i’ve seen this issue before on ES. From memory that time the recommendation was to use kelly kbs controller since motor back emf is square shaped.
Motor might be poor match for sine controller.

What is your battery voltage and what is motor kV?
Do you get any errors at all in program?
Have you changed PID parameters from default?
 
The battery voltage is 48V (13S Li-ion), I don't really know the motor's kv. I could measure it. My plan was to see how it runs, and adjust the chain sprocket size according to the results.

I don't get any error when I change settings on the controller.

I tried the default PID values, and I also tried to tinker with them, still no luck.
 
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The displayed speed is quite erratic, you can see it on this video : https://mega.nz/#!9FZgkSBQ!2We1l1p6rBtGSsu_U67SMiofROuMwd8b8ypjRHWuvnY
 
The speed in kelly readout is always a bit erratic.

I could not find the post i was looking for, only this:
https://endless-sphere.com/forums/viewtopic.php?t=98568#p1458573

Don’t think you’d be able to know the kV without a scope since there is doubt that controller limits rpm. Try it with real load (driving).
wheel and chain will not be enough load.
 
It's one of those Big Block motors and they work terribly with Kelly sine wave controllers.
I had to go with a sensorless trapezoidal controller from Greentime to get it to spin properly.
 
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