Modified PWM Technique For Torque Ripples Reduction In Three Phase PM BLDC Motors

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dc.contributor.authorSalah, Wael Abdel Muhdi Yacoup
dc.date.accessioned2018-10-19T02:08:07Z
dc.date.available2018-10-19T02:08:07Z
dc.date.issued2012-04
dc.description.abstractPermanent magnet (PM) brushless DC motors are used in many applications due to their high efficiency, high torque density, and compact sizes, which make this type of motors more popular over the other types. This research work focused on torque improvement of PM brushless DC motors by minimizing the generated torque ripples during the commutation period. The approaches and methods adopted in this project are presented thoroughly, along with the mathematical analysis and Matlab-Simulink modeling. Torque ripples in PM brushless DC motor drives usually originate from the motor design structure and from the control side in the form of current ripples. The torque ripples coming from the control side appear in the form of spikes and dips on the output torque. They occur because of phase current rate mismatch during the phase current commutation period. Practically, the current rise and decay rates between the phases are not equal, where the current in the energized phase reaches its maximum value before or after the de-energized phase current reaches zero. Hence, the main objective of this research is to estimate and control the rate of the energized phase current to match approximately the de-energized phase current rate during the current commutation period. As a result, the torque ripples are minimized. To accomplish this objective, a modified pulse-width modulation (PWM) strategy is applied to the energized phase to slow down the phase current at low speed and to speed up the phase current at high speed. A comparison between the modified PWM and the conventional control techniques showed a 45% average reduction in torque ripples when the proposed technique was applied under different loading conditions and at different speeds. Experimental results of the proposed technique, in general, indicated a torque ripple factor reduction compared with conventional PWM control. To summarize, results indicated that torque ripples are effectively reduced when the PM brushless DC motor drive operates within the constant-torque operating region. Therefore, the experimental and simulation results of the modified PWM technique validated and verified the functionality of the proposed strategy.en_US
dc.identifier.urihttp://hdl.handle.net/123456789/6816
dc.language.isoenen_US
dc.publisherUniversiti Sains Malaysiaen_US
dc.subjectModified PWM technique for torque ripplesen_US
dc.subjectin three phase PM BLDC motorsen_US
dc.titleModified PWM Technique For Torque Ripples Reduction In Three Phase PM BLDC Motorsen_US
dc.typeThesisen_US
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Pusat Pengajian Kejuruteraaan Elektrik dan Elektronik - Tesis