Design and construction of a controller for mitigation of torque ripple in a brushless DC machine

“In this research, a technique of eliminating the torque ripple produced by a brushless DC machine is developed. The torque ripple is eliminated by controlling the amplitude and phase of the machine’s stator current harmonics. The stator current harmonics are determined using control laws that require measured (or estimated) values of torque ripple as feedback. In this case, the torque ripple is measured using a piezoelectric sensor that detects strain in the motor mount. Simulation and hardware verification are used to demonstrate the effectiveness of the torque ripple mitigation strategy”--Abstract, page iii