Vibration analysis of BLDC motor drive employing model reference adaptive controller

The drive industry ensembles the stable operation of the motor with a perspective to adapt to the needs of the application and ensure the required delivery of power. It necessitates measures for arbitrating both the electrical and mechanical disturbances through the use of feedback control mechanisms and bring out its ability to cater the desired performance. The paper introduces the theory of the model reference adaptive control (MRAC) with a view to minimize the effects of vibration of the brushless dc (BLDC) motor. The emphasis owes to reflect the regulatory disturbances in terms of regulating the speed and therefrom observe the variations in the cogging torque, which contributes to be the primary reason for inducing vibrations in the motor. The forces calculated from the torque output of the MRAC controller form the input to estimate the amplitude of displacement experienced by the BLDC motor. The study relies on the finite element method (FEM) based structural harmonic analysis for the motor, to realize the variations in the displacement corresponding to the output of the MRAC. The efforts relate to minimizing the cogging torque and therefrom bring out the efficacy of the MRAC over the conventional PI controller in being able to lower its effects over a range of vibrating frequencies and thus claim its suitability for use in similar other motor drives.