Feedback-Based Mitigation of Torque Harmonics in Switched Reluctance Motor Drives

An issue that often arises in switched reluctance machine (SRM) drives is excessive vibration/noise created by harmonics of electromagnetic torque (torque ripple). In this research, a closed-loop control technique is developed to eliminate torque harmonics produced by a SRM. A piezoelectric washer has been designed and incorporated into a SRM drive system to sense harmonics of torque-ripple-induced vibrations. Simulation and laboratory experiments are presented to validate that the sensor output is correlated to torque ripple. To mitigate the undesirable torque harmonics, a gradient algorithm is used to minimize the measured vibration harmonics by adjusting current magnitude components. The control is discussed in detail and simulation and hardware results are presented.