Robust Current Controller for IPMSM High Speed Sensorless Drives

This paper proposes a new current controller for high speed drives of IPMSM position sensorless control. It has been pointed out that the conventional current control system with low performance design becomes unstable under high speed region. First, this paper shows that position estimation error cause unstable phenomenon, and this instability is especially emphasized under high speed region. To overcome this instability, simply modified controller with 2DOF structure is proposed in this paper. Stability using the proposed current controller is then analyzed theoretically, and the proposed controller can enlarge robust stable region for IPMSM position sensorless control, and some experimental results show that the proposed controller is superior to that using conventional one.