Torque ripple analysis and reduction for wind energy conversion systems using uncontrolled rectifier and boost converter

Dr Khaled Hani Ahmed

Research output: Contribution to journalArticle

51 Citations (Scopus)


A conventional topology for a small-scale wind energy conversion system consists of a permanent magnet synchronous
generator, a diode bridge rectifier, a boost converter and a grid-side inverter. Since generator phase currents contain low-order
harmonics and cannot be controlled independently using a diode bridge rectifier, electromagnetic torque ripple is relatively
large and may have a detrimental effect on the life of the turbine through fatigue induced by shaft torque ripple. This study
investigates methods to reduce this electromagnetic torque ripple, from both the viewpoints of the circuit topology and the
control strategy. The effect of the DC-side capacitor on torque ripple is investigated and different control strategies and their
effect on torque ripple are compared and analysed. This shows that the torque ripple can be reduced by removing the DC-side
capacitor and can be further reduced by controlling DC-side current to a constant value. These methods have been
investigated theoretically and the validity of the results confirmed by both simulation and experiment.
Original languageEnglish
Pages (from-to)377 -386
Number of pages10
JournalIET, Renewable Power Generation
Issue number5
Publication statusPublished - Sep 2011


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