KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW)

[Daz]

Hello, I plan to buy a KT 60V 60A but the label on the controller says "KT60ZWSRK....". From my understanding ZW stands for square wave.

If I upload a new FW with the tool, will it run sine wave simplified FOC?

An other question : is it possible to run at 64v (16s battery) without any mods a KT labeled as 48V dc; this one for instance :

cheers

i run my KT 48v controller on 16s but charge to 62.8v

there are 63v capacitors in mine, my understanding is 63v

16s is usually charged to 67.2V

my understanding is that you need to stay under the 63V for most 48V controllers in general

running @16s i am not able to use the full capacity as i only charge to 62.8V but i get the higher power/speed maintained longer than running at 15s or 14s

hope that helps

 

[Tepa76]

I found something intresting while playing with the firmware and settings. I mapping the motor spec angle for finding best maching.
I made this for a 2 year a go, but it leaving the feel that it was not perfect. So i did it now again with new instructions "wheel in air with full throttle without load".

Previously 25 deg would work for best.
Now i start from there "25°"by increasing angle by 5° steps and found that current and erps stay invariable until 45°. From here current starts to grow, but also i got more speed.. I continued until 65° when current measured externally was about 5,5A and erps is 400!! witch is about double from starting point .
I repeat this test with adding roughly 150W load to motor for confirm that i can increase the speed while loaded this way. okay by sacrificing the efficiency..

By degreasing the corr angle below 15° leads to current grow and reduce speed. No good!

Now question: Is this same as what happens in proper field weakening? I believe not, just courious if i add "bonus" angle to offset in certain needs eg activate (off-road and assist 5) simultaneusly would get me fast back home or propapbly really slow (pushing bike back without walk assist after smoke escapes) :lol:
Thoughts!?


Ps 25-30deg fit nicely in middle of sweet spot, so i will continue for using it.
Diagnostic screenshots below,

Cheers,

 

[marka-ee]

I'm reading a lot of this thread but am wondering about the maturity of this FW. So many questions of phase angle settings, rough running, various other settings that in my opinion, quite frankly looks like alpha level status at this point. I Asked a few days ago: What are the real world measured advantages achieved by this FW as far as wh/KM results ( efficiency ) and top speed results with a before-after using same bike, battery, etc. You know, as in basic scientific method. FOC sounds wonderful, but , ummmm, does it work on the road ??? I admire the work of the two ( competing ? ) developers, but in 171 pages is there some road testing that I missed ? Thanks

 

[sdobbie]

I'm reading a lot of this thread but am wondering about the maturity of this FW. So many questions of phase angle settings, rough running, various other settings that in my opinion, quite frankly looks like alpha level status at this point. I Asked a few days ago: What are the real world measured advantages achieved by this FW as far as wh/KM results ( efficiency ) and top speed results with a before-after using same bike, battery, etc. You know, as in basic scientific method. FOC sounds wonderful, but , ummmm, does it work on the road ??? I admire the work of the two ( competing ? ) developers, but in 171 pages is there some road testing that I missed ? Thanks

The software definitely comes across as pre alpha. I really appreciate the effort that has went into it but it makes my motor draw over 100 watts no load and sound like a tractor engine, whereas a cheap squarewave controller off ebay makes it run smoothly and quietly drawing under 20 watts at full speed. I have spent hours trying angle settings. The only settings I haven't played with are the hall angle settings 1 to 6 but they make absolutely no sense. My motor has 3 sensors, not 6.

 

[stancecoke]

Is this same as what happens in proper field weakening?

Yes, of course. Field weakening is nothing else than a "too big" advance angle.

What are the real world measured advantages achieved by this FW

My main motivation for the project was the possibility to use a torquesensor directly with the controller with no need for an ugly and expensive thing like the Cycle Analyst (sorry Justin )
It works without any problems for many users with very good effiency. No difference to the stock firmware.
If you want simple PAS or throttle operation, there's no need to use the open source firmware.

The Kunteng hardware is very limited, a poor 8bit processor with no possibility to do "real" FOC. Therefore I concentrate on the Lishui hardware for about two years now. The Lishui firmware is ported to the very cheap an widely available controller of the Xiaomi M365 scooter, also.

regards
stancecoke

 

[sdobbie]

Can someone please help me understand the hall angle 1 to 6 settings? My motor only has 3 sensors.

 

[stancecoke]

understand the hall angle 1 to 6 settings?

the three sensors have 6 on/off combinations during one electrical revolution.
Each switch is assigned to a certain rotor position. Due to manufacturing tolerances the positions can vary slightly. Setting them manually is not necessary normally, it's only for fine fine tuning...
@mspider65 has just given a lecture to this topic
https://endless-sphere.com/forums/viewtopic.php?f=30&t=110121

regards
stancecoke

 

[sdobbie]

Thanks, had a good read of it but I still don't understand. In the image there is two instances of each hall angle along the bottom, which one do I use? 5 transitions at 0 and 360 for example. I am pretty sure the hall sensors in my motor are 30 degrees apart and not 60

 

[Vbruun]

I quite like this firmware because it is well adapted to running with a torque sensor. I am thinking of using it on a mid drive (bosch) that has no halls but the moment a sine/cosine rotary encoder installed. Would I be correct in thinking that I could swap out the rotary encoder for the RMB28IE / RMF44IE encoder?

Link to data sheet: https://www.rls.si/eng/fileuploader/download/download/?d=1&file=custom%2Fupload%2FRMB28D01_16_EN_data_sheet.pdf

 

[raedet]

Quick question
is this OSFW compatible with the S-KU63 controller if not what are the required modifications (maybe changing CPU?) or do i really need the KT36 or S06S controller? i'm a rookie on these subjects its for a school project

 

[geofft]

Quick question
is this OSFW compatible with the S-KU63 controller if not what are the required modifications (maybe changing CPU?) or do i really need the KT36 or S06S controller? i'm a rookie on these subjects its for a school project

The usual problem with using non sinewave controllers with this fw is the lack of a current sensor. This means that the FOC can't operate which seriously impairs the efficiency.

Some controllers have the facility to retrofit a current sensor (ACS711 or similar), I've no idea if the KU63 is one of these. You'll find several references to this elsewhere in this thread, but I've no experience of doing this.

Probably easiest just to buy a compatible sinewave controller... :wink:

 

[sdobbie]

I have been doing more experiments with the pwm off at coast feature but it doesn't work properly.

If I accelerate from standstill by leg power alone, there is no resistance from the motor and it works as expected however, as soon as I use the throttle for a bit of extra power, there is resistance felt from the motor even if I completely release the throttle. The only way to get rid of the resistance is to bring the bike to a stop for a few seconds then start pedalling again.

 

[marka-ee]

The usual problem with using non sinewave controllers with this fw is the lack of a current sensor. This means that the FOC can't operate which seriously impairs the efficiency.

'Seriously impairs' ? Any road tests by someone to support this claim?

 

[geofft]

'Seriously impairs' ? Any road tests by someone to support this claim?

I remember during earlier testing of the fw at one point I tested the difference between FOC on/off with the bike on a heavily loaded training roller. The difference was very noticeable, with foc 'on' the motor sounded and felt much more lively and the achievable top speed increased from 14mph to around 18mph.

It would be fair to say that higher speed doesn't necessarily equate to higher efficiency, so maybe 'noticeably impairs motor performance' would have been better chosen words, but for sure it made a difference.

 

[stancecoke]

The only way to get rid of the resistance

Hm. Are you sure, there is a measuralbe resistance? e.g. if you stop pedaling at 20kph with PWM on you reach 0 kph after a significant shorter distance than with PWM off?!
Are you sure, that the X4 throttle settings are OK? Is the resistance the same with the old version, when regen can only activated by the brake lever? If yes, there is something wrong with the current offset.
You can try to fine tune the offset in line 79 of the adc.c Try values from -10 to +10.

https://github.com/stancecoke/BMSBattery_S_controllers_firmware/blob/18fdd5ce9479425b2fba97a2997f7b2d5f4d27f5/adc.c#L79

regards
stancecoke

 

[sdobbie]

Hi, I was playing about with current cal a in the app to make the current display in the app match what my multimeter was showing. I take it that the current offset is not the same as changing the cal a setting in the app? Is cal b a decimal where I change it in steps of 0.1?

I was doing the experiments with the bike upside down and turning the pedals with my hand and there is a definite resistance there. With a bicycle, that resistance including the higher idle consumption will impact efficiency and probably negate any gains from regenerative braking and foc.

 

[Anonymous95]

Good evening everyone,
I have a fat bike with 1000w motor, 48v 20ah battery, the controller is a dual mode KT bluetooh. Having problems like that the bike jerks in a few moments, I started investigating. I discovered the cause by doing various tests with my bike and that of a friend of mine with 1500w motor and KT bluetooth control unit. We realized that the problem occurs only if we use the bike without the app (KT smartbicycle). So if we use the app the bike works well, but if we use the display without the app the bike gives problems and jerks. We have a lcd5 and a lcd8h. The parameters are the same both on the app and on the display. I tried to unplug the dongle from the controller but nothing changes. Do you have solutions? We don't want to keep the app running all the time.

I tend to point out that, both my friend and I have this problem so I'm thinking kt bluetooh controllers suffer from this problem.

Thanks to everyone who will answer and sorry for my bad English.

 

[Anonymous95]

Help me

 

[sylvain_wm]

Hi everyone,
I bought a KT72V and a 72V battery, my motor is a 48V.
Can I use the 48V motor with this voltage?
In my opinion, there is no problem but I'd like to be sure...

have good day.

 

[mehmetoz1980]

Maybe,if reducing the current it not be a problem.so the strength does not increase too much

I have 48v motor too (golden motor magic pie 5)

I've read many high voltage mods to my motor.
this is a dd motor.

I think,more suitable in this regard.

In this case it is wise to use a temperature sensor.

 

[sylvain_wm]

Thank you for your reply.

 

[sylvain_wm]

Hi,
I bought a KT72VSVP. I tried to program it and it doesn't work.
I have already programmed a KT48VSVP, and had no problems.
I dont know what to do.
Does somebody have an idea?

Have a good day.

 

[atkforever]

Hello Sylvain,

Can you give more details about what isn't working? Can you flash it properly?

Maybe your undervoltage limit is too low or If you use no display there are 2 wires on the display socket to short : red and blue.

 

[sylvain_wm]

Hi,

I can flash it.
The LCD display works but :
- the speed remains at zero while I pedal.
- the battery indicator remains empty while the voltage display by the LCD is 81V.
I checked the speed signal, the torque and PAS signal...
The hall sensors work well...
Here is the screenshot of my OSEC configurator.

 

[sdobbie]

Does anyone have a schematic for the KT controllers? I was especially interested in a diagram of the 12 fet one. I was also considering removing the dissipation resistor and replacing that with lm2596hv step down module to reduce power consumption.