| Abstract |
The paper investigates various non-linear observer-based rotor position estimation schemes for
sensorless control of permanent magnet synchronous motors (PMSMs). Attributes of particular
importance to the application of brushless motors in the automotive sector, are considered e.g.
implementation cost, accuracy of predictions during load transients, the impact of motor saliency and
algorithm complexity. Emphasis is given to techniques based on model linearisation during each
sampling period (EKF); feedback-linearisation followed by Luenberger observer design based on the
resulting ‘linear’ motor characteristics; and direct design of non-linear observers.
Although the benefits of sensorless commutation of PMSMs have been well expounded in the
literature, an integrated approach to their design for application to salient machines subject to load
torque transients remains outstanding.
Furthermore, this paper shows that the inherent characteristics of some non-linear observer structures
are particularly attractive since they provide a phase-locked-loop (PLL)-type of configuration that can
encourage stable rotor position estimation, thereby enhancing the overall sensorless scheme.
Moreover, experimental results show how operation through, and from, zero speed, is readily
obtainable. Experimental results are also employed to demonstrate the attributes of each methodology,
and provide dynamic and computational performance comparisons. |
