Torque estimation for synchronous reluctance motors using robust flux observer to magnetic saturation

This paper proposes a robust torque estimation strategy for synchronous reluctance motors (SynRMs) to magnetic saturation using a full-order flux observer, which is based on a new linear flux model. SynRMs possess considerable magnetic non-linearity, which causes difficulty in obtaining optimal torque control. Thus, to realize optimal torque control, the torque profile needs to be defined according to current amplitude and phase. Finding torque profile, however, also tends to be complicated due to its magnetic non-linearity. This paper proposes a simple torque estimation technique using a full-order flux observer, which can realize torque estimation that is less sensitive to magnetic saturation and core loss. In addition, experimental results show the feasibility of the proposed strategy in this paper.