Which position sensor should be used in my PMSM control system?

Hi

For such applications (low speed position control)  linear Hall sensors are best choice, you can search for " linear hall sensor based PMSM" on google you will find IEEE paper from some university, very well explained.

Thanks and Warm Regards

Venkat

Ray,

Depending on how slow your speed and position requirements are you should be able to use just a QEP sensor.  With InstaSPIN-MOTION we've been able to smoothly control a PMSM at and below 1rpm using only a 4000 count/rev QEP encoder.  In addition to having excellent zero speed control.  

Dear Adam

Some applications QEP could be costly, linear Hall sensors can also be used, do you have any coment?

Thanks and Warm Regards

Venkat

Venkat,

I agree.  There are many applications were QEP is going to be too costly or cannot be mounted.  Linear halls would be a good choice for those applications.  The biggest drawback with linear hall sensors from my experience is the algorithm to decode the rotor position.  It is simpler to to use a QEP sensor.