250W e bike geared Motor

Dear Team,

I have order this motor,
Ebike 36V / 48V 250W Front/Rear Rotate/Rear Cassette Brushless Gear Hub Motor | eBay

and its respective accessories also I have hardware to opertare the motor.

I written trapezoidal code and try to run the motor but motor creates very high noise and consumes more current in trapezoidal commutation.

same code I tried with other motor and they are working very well.

[ Actually inside a motor there is gear system may be because of that its behave like this ]

I did one test case where I have connect Chinese controller to the motor and captured some waveform and waveforms are weird its not like pure sine wave
##without filter 2 phase with respect to GND on oscilloscope

At the end FOC generates sine wave across the phase but as per the above waveform its not like sine, so what kind of commutation is required to operate this type of motor?


Can I control this motor using simple FOC algorithm ?

I am used to with stm32 blue pill

Hi @jayvant , welcome to SimpleFOC!

I would say probably yes. It’s hard to see the real specs from the eBay listing, but in principle it should be possible. Does it have Hall sensors? If not, it might be difficult to mount a sensor on the rotor, if the output is via a built-in gear-train… to do FOC you need closed loop sensing of the actual rotor position.

it’s hard to say but it looks like maybe in this waveform we see a lot of the PWM as noise? If it is using low-side shunts it’s hard to capture with an oscilloscope. You should measure the phase currents inline…

It will be either trapezoidal or sinusoidal commutation waveforms, but it should really work with either type. Using the right type will be a bit more efficient and less noisy.
Were the other motors you tested your code with of the same power levels and KV ratings? Maybe its an issue with the code and the parameters of this motor?

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The listing says that it does have hall sensors, so yes you should be able to drive this. Standard procedure is to get your electronics working ouputting a three phase sine wave open loop, then get the sensors working ok, then connect them and get the code working in more detail. There are better posts on standard proceedure, saw one from Deku recently, use the search function.

I don’t know what board to use for this.

You will not be able to see the sine wave with an oscope, unless you measure the current through the motor using e.g. a sense resistor, you can get cheap 0.1 and 1 ohm resistors made for speakers which have large power handling capabilites.