A Harmonic Compensation Method for SPMSM Sensorless Control Based on the Orthogonal Master-Slave Adaptive Notch Filter

In this article, a model-based sensorless control method which incorporates the orthogonal master-slave adaptive notch filter (ANF) for surface mounted permanent magnet synchronous motor is proposed. Since the rotor position estimation is seriously affected by the harmonics of estimated back-electromotive force (EMF), the orthogonal master-slave ANF is designed to deal with this problem. The orthogonal master-slave ANF is developed based on the ANF with frequency adaptation. The theoretical analysis indicates that the orthogonal master-slave ANF can accurately track the specific harmonics and the fundamental wave of back-EMF. Both the satisfactory harmonics elimination and the fast response speed of filter can also be achieved at the same time. Besides, the proposed frequency adaptation algorithm overcomes the dependence of frequency convergence on the signal amplitude and the problem of “double-frequency oscillation” in the estimated frequency. And since the use of frequency adaptation, the phase-locked loop is unnecessary, which simplifies the system and enhances the reliability. The corresponding experimental results under different conditions demonstrate the effectiveness and the superiority of the proposed method.