Full speed range sensor less control for PMSM using an adaptive extended Kalman filter

Abstract

The combination of two sensorless technique for permanent magnet synchronous motor (PMSM), namely Direct Flux Control (DFC) and back electromotive force (BEMF) based technique, is presented within this work. The issue of implementing a complete speed range sensorless control of the electrical machine is addressed. The idea is to use a Kalman filter in order to estimate the entire state of the machine using only the measured currents. The system variables can be observed thanks to the BEMF components. The complete observability of the system state is maintained also at standstill operation by adding the Direct Flux Control signals to the measurements. The aim of this work is to obtain a smooth combination between these two technique in order to robustly control the motor.