A New Identity Dimensional D-State Observer for Sensorless Drive of Permanent-Magnet Synchronous Motors

Abstract

A new identity dimensional D-state observer whose state variables are the stator reaction flux and rotor flux is proposed for the sensorless drive of permanent-magnet synchronous motors. Furthermore, sufficient conditions are newly and analytically derived for the observer gains that guarantee stable convergence of state variable estimates. Additionally, two new methods for designing observer-gain are presented; these methods—the constant and speed-dependent gain-methods—satisfy the derived analytical conditions. The observer gain conditions used in these design methods are validated through extensive numerical experiments. In addition, typical design examples of the observer gains by using the proposed design methods are presented.