Design of a Closed-loop Controller for Mitigation of Torque Ripple in a Brushless DC Machine


Brushless DC machines with non-sinusoidal back-emf are often characterized by significant torque ripple that occurs as a result of the interaction of back-emf and stator current harmonics, as well as cogging torque. In this paper, a method of mitigating the torque ripple is described that utilizes closed-loop feedback control. Specifically, the torque ripple produced by a machine is measured using a piezoelectric sensor. The sensor is constructed from polyvinylidene fluoride (PVDF) film, which produces a voltage in response to subtle strains in the motor housing. The sensed torque ripple provides a feedback that is used to determine stator current harmonics utilizing a controller that is based upon cost function minimization. Simulation and experimental results are used to demonstrate the effectiveness of the control technique.

Meeting Name

2003 IEEE 34th Annual Power Electronics Specialists Conference


Materials Science and Engineering

Second Department

Mechanical and Aerospace Engineering

Document Type

Article - Conference proceedings

Document Version


File Type





© 2003 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Jan 2003