Configuring Votol em200 controler to work with a small bldc motor

[Jeff23spl]

Hello

Story:
Last year i moded a brushed 500w PB batteries kick scooter into a lithium bldc ride.
I bought a cheap 48v 2000w kit from Vevor. (I think it is same as Kunway.)
I made a 14s6p pack of 18650 3Ah 2.5c cells and connected everything to work fine with it including hall sensors.

Acceleration results are geat (A lot faster and torquier than before) but cruising and low speed riding isn't. The controler feel like if it is set for speed target rather than targetting torque. (Small throttle input makes heavy acceleration to reach that low speed as quick as possible rather than reducing torque.)
I tryied the 3 speed switches, 2-3 different throttle and even adding resistors to find a way to make it smoother without any success.
The cheap controler is similar to the one of low cost e-bike kit and doesn't look programmable. (Square aluminium box with fet bolted on the side and a bunch of wires in just 1 end).

I ended up looking for a replacement controler that can be programmed for a smoother ride and i would also like to have flux weakening to gain top end speed without reducing low end torque to climb a hill.
Space is limited but i could fit a EM50-4 in there.
Why Votol? because i have a EM200 in hands for another project and i'm assuming if i can make it work with the EM200, i can buy a EM-50-4 without any risk of non compatibility. (The EM200 is from a kit with a QS138 V3 that i bought for a later E-motorcycle project into a Yamaha 1977 frame...)

The EM200 look to be factory set to fit the QS138 V3 motor and that combo worked great when tested unloaded.
-I lowered the voltage setting on the controller to fit my 14S pack and let everything else as per factory. (I don't want to lose the match for the QS138)
-I successfully paired the hall sensors of the small veyvor motor to the EM200 controller. (Color was almost matching so it was easy)
-I temporary connected the controls of the E-motorcycle to test the controler on the kick scooter. (Motor is mid size chain driven to the rear wheel. Wheel is up in the air for testing purpose)
When i slowly increase throtle it start correctly so i expect phase angles and polarity is ok but it start to jerk, when i push the throttle further.
I measured the RPM and it reach faster speed at part throtle than it was going on it's own controler before reaching the point where it start to jerk. This is driving me to believe that flux weakening might be the problem.

Question:
Information on Votol controlers seem hard to find. Just to figure out the wiring diagram took me some time and the website manual is not giving much infos about it. I could try some values without any clue but i don't even know if i need to reduce or increase the number to limit the flux weakening.
Is anyone here more familiar with those controlers and could help me understand how flux weakening parameters works ?

Can the fact that the controler is 4-5time more powerfull than my motor make the readigs to go nuts because the signal isn't strong enough ?

Can the test with the wheel in the air affect the results ? The load is small and chain backlash may return an oscillating current feedback...? I'm afraid to try it on the ground because when it start to jerk, it keep going when i let off the throtle, i have to stop the controler to stop it.

thanks

 

[amberwolf]

A torque (current) -modulating throttle controller will essentially go full speed without a load even at a tiny amount of throttle, because it takes very little torque (current) for it to do this (usually an amp or two, or even less).

To really see what the throttle control is setup like you have to ride it, or setup something like a dyno (dynamometer), or one of those bike trainers (like the ones that tell you how much power you are putting out), to "ride" it on stationary and put the load on the wheel so you can tell how the throttle "feels", etc.


Most controllers (pretty much nearly all the cheap ones in kits) are speed-modulating (really they modulate the duty cycle of the PWM to the motor, which modulates the voltage, which in turn modulates the speed), so the throttle behaves about the same with or without a load.

 

[Jeff23spl]

A torque (current) -....

Thank you for explaining but the initial problem driving me to change controler was happening under load (with 140pound on the scooter) The tests run unloaded was only when i was trying to configure the Votol 200amps controler on a 40a motor

Since you spend time to talk about it, i will try to better explain what i was trying to say:
I agree with you that controler power stage will modulate the output signals to adjust the average voltage seen by the motor and doing this, affect the resulting current and speed (RPM) (I do work with industrial variable frequency drives having similar caractéristics)
But the controler ''brain'' could drive the output level using few differents control strategies.... With industrial VFD i have options to select it but not with my Veyvor one.
The best strategy for mobile use, is probably to use torque control (amps). The throttle input send a signal to say how much current you want to use and motor reach a speed rpm reverse proportional of the load it need to drive. Light load = greater accel and speed vs the opposite with more load. Exactly like the carburator plate on a thermal engine...
Differently, a machine or tool, would need a different strategy where we want to track a fixed speed. The signal input give a specific motor rpm target and the controler automatiquely change voltage/current to reach and keep that target rpm. if rpm decrease controler rise voltage and the opposite if rpm increase....
When i try to softly ride that Veyvor controler compared to my other rides (2 brushed kick scooters and a bldc geared hub ebike) this veyvor have a totally different reaction feeling. It seem to act like the machine tool explained above by giving the full torque regardless of throtle input and settle down when motor get up to speed. Instead of slowly accelerate with a small input signal like a torque control should do.
It is hard to explain but i think the combo kit i got has been more designed for a machine tool than a kickscooter...This is the main reason why i want to replace it.

I was planing to try an E-bike controler to see if the program would react the same since i have an ebike with similar low cost square box controler that run very smooth instead of the Veyvor kit. But i think about the option to add flux weakening to my kickscooter to gain speed at the same time and ended up looking at Votol EM-50-4

My questions for this post was more about: how to configure Votol parameters to run a Veyvor motor. As explained, it is when i try to run the motor with my EM200 that it start to oscillate and i would like to stabilise it.

 

[j bjork]

Votol EM-100 & EM-150 controllers

Before I get into the details below, since this is not a controller-specific problem, is it ok if I split your posts and my replies off to a separate troubleshooting thread? (best to move them to your build thread if you have one). 1.4v is VERY low, below typical minimums, for a LiFePO4...

endless-sphere.com

 

[Jeff23spl]

Votol EM-100 & EM-150 controllers

Before I get into the details below, since this is not a controller-specific problem, is it ok if I split your posts and my replies off to a separate troubleshooting thread? (best to move them to your build thread if you have one). 1.4v is VERY low, below typical minimums, for a LiFePO4...

endless-sphere.com

I was already in the process of reading that huge thread. I did found a better manual in it that what was proposed by the SIA supplier. It is a bit weird but im happy to have it now.

I will keep going...

 

[88meet88]

I was already in the process of reading that huge thread. I did found a better manual in it that what was proposed by the SIA supplier. It is a bit weird but im happy to have it now.

I will keep going...

I've recently faced similar problem when i connected CY motor with Votol EM100.
on giving throttle it goes uptp certain RPM and oscillates with a wierd sound and jerking
Have u found any solution for same?
Please share me possible solution for that!

 

[Jeff23spl]

I've recently faced similar problem when i connected CY motor with Votol EM100.
on giving throttle it goes uptp certain RPM and oscillates with a wierd sound and jerking

For the Votol, i do expect it is jerking when it goes into flux weakening range. My last try would have been to do a motor autotune to see if it would help. I found some info about it on the above link provided by J Bjork. Im assuming the motor internal data parameters pre configured for a large and heavier motor may not work with the small one. But i did not, i was afraid to try it since my test controller was originaly matched with a motor that i plan to use on another projet. I don't want to end up with a controller that jerk on both motors when it was working ok with the large one i bought it for.
I just did some try to reduce flux weakening action but i was not sure exactly where to set it and which directions to go (Increase or decrease value) So i made some try around flux parameters but never found a direction that would help it.
I did even contact the company that sold it for help but they just sent me the incomplete manual that i did already found.

After this, I was looking for web deals on a small votol to do safe experiment but i ended up buying a genererique ebike controller with a remote display allowing some configuration. There is no flux weakening functions with this but it give me the low speed smoothness that i was looking for to ride slowly on campgrounds without sacrifice on power when you want it. It was also ''plug and play'' nothing to mess with. I got 5 power level instead of 3 set by display and the first one really work as a power level reduction decreasing torque and speed like i want not just a max speed limit like my older controller.

 

[glennb]

Votol run those motors beautifully without field weakening.

You’re 90% of the way there. If you want to post config screenshots I can tell you what changes to make.

 

[Jeff23spl]

Votol run those motors beautifully without field weakening.
You’re 90% of the way there. If you want to post config screenshots I can tell you what changes to make.

i ended up using an ebike controller for my kickscooter to run the vevor kunray my1020. But im still interrested to know for knowledge how to disable the flux weakening if i need to with another project...

Unfortunately, i just have printed the parameters that was pre-configured for my qs motor...

On the other hand, can you confirm if field weakening isn't possible with that motor type and why .....or it is a matter of compatibility between Votol and My1020 ?

 

[glennb]

I don’t know about FW incompatibility. I had a quick play with it, but saw no point in using it when you can simply either increase the voltage, or reduce the gear reduction.

You’re limited by power with this motor. 60km/h at not much more than 6000rpm is all you should be aiming for, and that’s riding in an aero position.

With your setup you’ve no need for multiple power levels, or field weakening.

Sensible configuration would be 40 battery amps, unlimited phase amps, then gear it up for higher speed. If the higher gearing doesn’t improve your top speed, neither will FW, because you’re power starved.

You might be tempted to try 45A battery amps, and might get away with it with low gearing, but the sensible way to supply more power would be by upping the voltage. The act of upping the voltage to increase power will also increase RPM, and thereby your top speed, so you’re once again in a position where FW is redundant.

FW is only practical where your top speed is hampered by RPM and/or gearing options rather than power. That won’t be the case with this motor unless you’re driving a lightweight velomobile that already has very tall gearing and you’re trying to break land speed records.

That’s my take on it, anyway.

As to how to disable FW … just use the “low” power level (set to 100) and ignore the FW fields.

Hope that helps.