speed feedback fault

[bernhard2]

Posted on January 15, 2014 at 11:41

Hello.

I've set up the a project with the MC lib from ST, but I run into issues with the hall sensors (I suspect). When I try to start the motor via the MC workbench, the motor makes a small hitch and then stops. The workbench reports a speed feedback fault.Below are some scope shots which show on CH1 the voltage applied to ''phase A''. CH2-4 show the hall sensors 1 to 3.The images show that the motor control starts operating but stops after the first few edges from the hall sensors. I already tried increasing the ''Input capture filter duration'' and the caps for the hall sensor signals but no luck yet.Does someone of the experts have an idea what might be wrong in my setup?(BTW. I also tried the sensorless configuration, there the motor runs for a few seconds but then stops with start-up failure, I'm not sure if this is related?)cheers,bernhard

[Gigi]

Posted on January 23, 2014 at 15:37

Hard to say Bernhard...

From the capture is seems that it is caused by a noise problem. For instance in the last capture the switch off of the PWM anticipate the green commutation, but you already tried increasing the filter... I don't think that the sensorless startup-failre and the sensored fault can be related. Which hardware are you using? The current regulation is good? In sensored configuration, in IDLE state, if you spin-up the motor by hand, are you able to read the measured speed (using WB or LCD)? Do you compute in the correct way the ''Placement electrical angle'' for the HALL sensor? Ciao Gigi