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dc.contributor.supervisor Filizadeh, Shaahin (Electrical and Computer Engineering) en
dc.contributor.author Mehrizi-Sani, Ali
dc.date.accessioned 2007-09-14T17:00:06Z
dc.date.available 2007-09-14T17:00:06Z
dc.date.issued 2007-09-14T17:00:06Z
dc.identifier.uri http://hdl.handle.net/1993/2819
dc.description.abstract Pulse-width modulation methods are widely used for the synthesis of ac voltages at the terminals of a voltage-sourced converter (VSC). Traditionally sinusoidal pulsewidth modulation (SPWM) has been used. A powerful alternative for this purpose is space-vector modulation (SVM), in which the converter is placed in a finite number of states in order to best approximate the reference voltage. This method offers better utilization of the dc bus voltage and provides several degrees of freedom for enhancement of the harmonic spectrum as well as switching losses. This thesis studies the SVM method for two- and three-level VSCs. A model for implementation of SVM in the electromagnetic transients simulation program PSCAD/EMTDC is developed. The model is able to generate firing pulses in linear as well as overmodulation range and is used to study the performance of different SVM strategies in terms of their harmonic spectra and associated converter and harmonic losses. The model is also used to demonstrate the suitability of the method for network applications. The thesis also employs genetic algorithms to find an optimized SVM sequence for improved harmonic performance. An objective function is defined that seeks to minimize the most significant harmonic components of the generated waveform, while keeping the other harmonic components within the acceptable range outlined in the available standards. The obtained sequence shows great improvement over the conventionally-used SVM sequence. en
dc.format.extent 1139801 bytes
dc.format.mimetype application/pdf
dc.language.iso en_US
dc.subject harmonic analysis en
dc.subject genetic algorithms en
dc.subject optimization en
dc.subject space-vector modulation en
dc.subject switching losses en
dc.subject transient simulation en
dc.subject voltage-sourced converter en
dc.title Advanced modulation techniques for power converters en
dc.degree.discipline Electrical and Computer Engineering en
dc.contributor.examiningcommittee Gole, Ani (Electrical and Computer Engineering) Wachal, Randy (Manitoba HVDC Research Centre) en
dc.degree.level Master of Science (M.Sc.) en
dc.description.note October 2007 en


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