Sensorless control of PMSM in a ultra high speed region taking iron loss into account

The importance of ultra high speed (≥ 50 krpm) motor technology has surfaced for various applications including turbo-compounding system, engines, and air blowers. However, there are challenging issues in a high speed motor technology: 1) robust mechanical structure, 2) materials like low loss silicon steel and high tensile strength, and 3) control issues such as the PWM delay, the PWM distortion, and the iron loss. Especially, the iron loss is usually neglected in the general permanent magnet synchronous motor (PMSM) control. Aside from the motor efficiency, the iron loss alters the PMSM dynamic model. Since the iron loss is not reflected in the conventional sensorless methods, the angle error grows steadily as the speed increases to an extremely high region. In this paper, a sensorless control method considering the iron loss is proposed. It cures the angle error in a high speed region, and the performances are demonstrated through simulation and experimental results.