Cancellation of harmonic torque disturbance in permanent magnet synchronous motor drives by using an adaptive feedforward controller

Abstract

The effects of disruptive harmonic torque disturbances on permanent magnet synchronous motor drives originating at the mechanical load or from cogging can be mitigated by producing a counteracting electric torque. The study proposes using an adaptive feedforward controller (AFC) for this purpose. The AFC is designed to operate as an auxiliary loop in parallel with a field-oriented controller, which provides speed control. The AFC input is the motor speed control error. The loop is tuned at the frequency of the harmonic torque and its output is added to the q-axis current reference as a variation current of the same frequency. The main advantage of the proposed method is that it does not require an estimation of the disturbance torque. The theoretical analysis of the scheme is presented in the study. Experimental results are also presented in the study from a motor drive system where the mechanical load produces harmonic torques. The results demonstrate the effectiveness of the AFC in significantly reducing speed oscillations by cancelling the effect of the torque harmonic disturbance.

Vibration Suppression Using Vibration Coordinate System Based on dq Transform with Specific Frequency

“…Controllers using sliding mode control [2] [3], H ∞ control for the resonant vibration [4], and disturbance observer(DOB) [5] [6] [7] [8] have been proposed. Furthermore, an adaptive feedfoward cancellation(AFC) [9], a repetitive controller [10], and specific component reduction controller(SCRC) [11] have been proposed for suppressing the vibration caused by the periodic disturbance, the resonance, and others at the specific frequency. Firstly, the AFC consists of the triangular functions and the gain tuning structure.…”

Disturbance suppression for PMSM by a non‐linear composite controller based on two‐channel strategy

“…Except for these general modes, lots of non‐linear feedforward control strategies have attracted the attention of researchers. In [18], it selected an adaptive feedforward controller (AFC) to realise rotor speed tracking, and its results displayed that AFC can effectively suppress ripple disturbance. More significantly, it is much simpler than the feedback‐loop observer in application, because this strategy did not rely on estimation model of torque disturbance and estimation value.…”