Extended EMF Observer for Wide Speed Range （宽调速范围的扩展EMF观察者）.pdfVIP

Extended EMF Observer for Wide Speed Range Sensorless Control of Salient-pole Synchronous Motor Drives Takumi Ohnuma, Shinji Doki and Shigeru Okuma Department of Electrical Engineering and Computer Science, Nagoya University, Aichi, Japan Email: ohnuma@nagoya-u.jp, doki@nagoya-u.jp, okuma@nagoya-u.jp Abstract—This paper presents an observer-based position [7]. In the low frequency signal injection methods, the torque sensorless control method with signal injection. An extended ripple is available as information to estimate rotor positions electromotive force (EEMF) observer is suitable for salient- [5] or the optimum current vectors for the maximum-torque- pole synchronous motors, because position information of EMF and saliency are both included. Signal injection is needed to per-ampere (MTPA) control [8], [9]. Since the error signals are make use of the position information of saliency at low speed. included in the mechanical oscillations, it is necessary to be However, observer consists of a low-pass filter. Therefore, position sensitive to the mechanical system. Based on the mechanical information of saliency has not been used enough for the EEMF oscillations, the sensitivity to the position estimation is enough observer. only if the injected signal frequency is much lower such as a In this paper, signal injection method without torque ripple few tens of Hz, and the inertia is much lower [5], [6]. is applied to make effective use of the EEMF observer at low speed. The signal frequency can be selected in a bandwidth o