Sensorless Control of Interior Permanent Magnet Synchronous Motors: Estimated Reference Frame Approach

A novel speed-position observer for sensorless control of interior permanent magnet synchronous motors is presented. Proposed solution exploits the concept of estimated rotating reference frame to estimate the speed and position. Local stability properties are proven using Lyapunov's second method and converse theorem. It is shown that typical operating conditions of electrical drives provide necessary requirements for persistency of excitation. Experimental and simulation tests show that the sensorless speed control system, based on the proposed observer, provides an acceptable dynamics of the speed and position estimation in wide speed range. The sensorless speed control algorithm is suitable for the applications with medium requirements for speed regulation performance.