Abstract：The load torque disturbance will affect the control performance of permanent magnet synchronous motor (PMSM), and a two-degree-of-freedom controller with feed-forward compensation by measured or observed load torque can reduce the effects of the load torque disturbance. In this paper, several load torque observers for PMSM is studied which can observe load torque precisely based on the measured currents, mechanical position and speed, and no extra hardware is needed for the observer. The proposed full order observers can also observe the rotor position and speed based on the output of the mechanical sensor instead of the traditional speed calculation method, and then the differential calculation can be avoided, and the effects of the measurement noise and discretization errors can be reduced. Taking the observer based on Kalman filter as an example, the performances of the observer and feed-forward compensation are verified by simulation and experimental results.
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2010, Vol. 25 
