FOC+HALL UVW phase current curv problem

[cyt]

I use FOC+HALL and the motor reduction rate is 1:1.

But the phase current(one of UVW phase) is not sine wave as figure.

Is it normal? how come the U/V/W phase current curv is not sine wave?

what problem cause that?

Thanks

[chaaalyy]

Zoom in, it should be pwm modulated, as far, as i know ... Or does this show the math of the hall sensor channels ?

[cyt]

Hi chaaaly,

I can't catch that, could you say more detail?

I also use FOC with sensor-less, the UVW phase current is sine wave as figure.

but FOC with sensor(hall sensor), it is not sine wave, what's the problem?

Thanks

[chaaalyy]

good question... At 1st sight i din´t recognice the writings left of your 1st picture. So i thought, you show the direct phase measurements on yellow / magenta / green and the blue one ist the "cumulated" value of the hall sensors :( Sorry for that ....

But anyway: Sensorless it works and with halls, you get that "spike" ? strange... I would expect something like that vice versa (not used to it, but because of the moment, it measures the bemf)

[chaaalyy]

Just an idea: Do the sensors (one or all of them) or the timer, they are connected to, trigger any interrupt ?

[cyt]

Hi chaalyy,

it measures the bemf? do you mean that phase current curve of FOC with hall is not sine wave is due to bemf?

sensor-less doesn't measure bemf?

could you share more about it?

Thanks,

[cyt]

h1/h2/h3 hall sensors value is captured by timer(Input Capture),

one of three hall sensor signal changed will trigger HALL Timer CC1 IT

[chaaalyy]

Vice versa... Without sensors, it has to measure "something" to get an "electrical angle". If you use hall sensors, you have to tell the placement and offset of the sensors and so it can be calculated.

[chaaalyy]

Last weekend i ran into problems with a triggered interrupt in position control. I search for the thread, when i´m back home. Mabe (just maybe !) it´s something "similar" here. I never used hall sensors with st´s motor control. In my case it´s an incremental encoder with index, which causes the problem.