"do we need saliency to track initial position."
for a high frequency injection technique, yes
"In case of Surface pole mounted PMSM there is no saliency, in that case what is the approach"
extremely challenging to do initial position detection
have you looked at InstaSPIN-FOC solution? this has built-in start-up features without sensor and that very good for most applications. For those that must have a perfectly smooth start-up under all conditions there is an example which uses HALL sensors for initial start-up, then transitions to sensorless.
for a high frequency injection technique, yes
"In case of Surface pole mounted PMSM there is no saliency, in that case what is the approach"
extremely challenging to do initial position detection
have you looked at InstaSPIN-FOC solution? this has built-in start-up features without sensor and that very good for most applications. For those that must have a perfectly smooth start-up under all conditions there is an example which uses HALL sensors for initial start-up, then transitions to sensorless.