Analysis of Torque Control Stability of PMSM Sensorless Drives in Flux Weakening Region

Abstract

This paper analyzes the effect of angle estimation error on the sensorless torque control of the permanent-magnet synchronous motor (PMSM). The actual torque of PMSM may differ from the torque reference due to the angle estimation error in sensorless control. Furthermore, this torque discrepancy can cause instability in the control system, especially in the flux weakening region. In order to mitigate the adverse effect of the angle estimation error, the new torque feedforward method considering the transient angle error is proposed. The proposed method is verified through the simulation and experimental results.