State Estimation Error Suppression for PMSM Speed Observer Based on Hall Position Sensor

Hall position sensor is with low cost and it can provide a relative accurate position information. On the other hand, it also has drawbacks such as low position resolution; poor speed measurement continuity and serious information lag behind. The Luenberger speed observer takes advantages of motor model and closed loop control theory thus can provide favorable speed and rotational angle feedback signal when under vector control. However, when it comes to the digital control system, due to the fact the sampling period of hall signal is much longer than that of the control period, ideal observed results still cannot be obtained when using conventional observer parameters and structure design method. Based on the analysis for issues of speed observer when under real applications, an effective speed and rotational angle estimation method which combined the reduced-order observer and multi-sampling theory is proposed in this paper, it best take advantage of the real hall signal information and can provide speed and rotational angle estimation results at each digital control period, besides, theoretical analysis prove that an ideal estimation performance can be achieved. The effectiveness of the proposed algorithm is verified through simulation and experiment, which shows the control performance can satisfy the needs of medium and lower standard servo applications.