Unified Sensorless Vector Control of Synchronous and Induction Motors

In this paper, a unified theory for sensorless fluxestimation and vector control of induction motors and nonsalientpermanent-magnet synchronous motors (PMSMs) is developed.It is shown that an estimator and vector controller for one of themotor types can also be applied to the other, with only minormodifications necessary. Two candidate estimators are considered:a variant of the well-known “voltage model” (VM) and aphase-locked-loop-type speed and position estimator. These areapplied to both motor types, and evaluated experimentally. Forthe nonsalient PMSM, an important result is that synchronizationcan be guaranteed from any initial rotor position.
QC 20101012