Sensorless direct torque control of a surface mounted PMSM using high frequency injection

Abstract

This paper proposes the high frequency (hf) voltage injection technique to DTC drives with the objective of extending their performance to the low and zero speed region. The simplicity of the original DTC algorithm is not compromised. The hf carrier is introduced by the direct modification of the fundamental voltage vectors. The position signal is then obtained from the direct demodulation of the resulting hf currents. Both simulation and experimental results are shown.