부산대학교 도서관

Injection-based techniques for self-sensing control of electrical machines are well established for zero to low-speed. However, dynamic performance and disturbance rejection capabilities of the injection-based methods are limited compared to sensor-based solutions using an encoder. This paper identifies the bandwidth of the carrier separation filter as the key factor that limits the performance of self-sensing control. A generic analysis of self-sensing drives via base-band approximation of the carrier-separation filter reveals that the bandwidth of the position tracking observer is limited to one-third of the carrier-separation filter bandwidth. Otherwise, the poles of the tracking observer become oscillatory. The resulting maximal bandwidth of position tracking observer limits the peak load torque that the drive train can withstand until the position cannot be unambiguously tracked. To take this into account for future designs, a metric is introduced that describes the safe operating region in which the drive train can operate with self-sensing control. This paper investigates the safe-operation area of self-sensing control algorithms that apply state-of-the-art carrier separation techniques. Consequently, it proposes a new observer-based carrier separation technique utilizing the bandwidth-partitioning concept. The paper demonstrates that this concept increases the tracking bandwidth by 50% and leads to a significant increment of the safe operating region of self-sensing drives.