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The Global ETD Search service is a free service for researchers
to find electronic theses and dissertations. This service is
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Networked Digital Library of Theses and Dissertations.
Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
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Showing 1 to 2 of 2 (0.05 seconds)Spelling suggestions: "subject:"amplitudenspektren"" "subject:"ljudspektrum""
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Analys av PWM-mönster i Matlab / Analysis of PWM patterns in MatlabMilevski, Mikael January 2002 (has links)
<p>One of ABB Power Systems´s business areas is HVDC (High Voltage Direct Current) technology. HVDC is used for transmissions for both short and long distances. One of Power Systems’s products is called HVDC Light. </p><p>HVDC Light is a relatively new technology for power transmission, but have before only been used for motor drives applications. The technology is based on VSC (Voltage Source Converter) that uses a technique called PWM (Pulse Width Modulation). </p><p>There are a lot of PWM patterns that have been examined, but not in the field of power transmission where ABB Power Systems is working. </p><p>The different PWM patterns can be used for reducing switching losses or harmonics, that can cause the need of external filters to decrease or increase. </p><p>The purpose of this report is to give a general picture of the system that generates the PWM patterns. The report describes some main components in the system. T</p><p>he thesis also present amplitude spectrum from various PWM patterns - generated by signals that have been pulse width modulated with a triangle- shaped wave. </p><p>By showing the frequency-content, the decisions are eased for the engineers and technicians that are working with this kind of questions. </p><p>An analysis of different PWM patterns have been done. The kind of reference waves that generate the PWM patterns are called Dead Band PWM and Modified SPWM. </p><p>Comparisons have been done for Dead Band PWM, between harmonics and the width of Dead Band. Comparisons have been done for Modified SPWM, between: </p><p>1. fundamental frequency and modulation index. </p><p>2. different Modified SPWM and their harmonics.</p>
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Analys av PWM-mönster i Matlab / Analysis of PWM patterns in MatlabMilevski, Mikael January 2002 (has links)
One of ABB Power Systems´s business areas is HVDC (High Voltage Direct Current) technology. HVDC is used for transmissions for both short and long distances. One of Power Systems’s products is called HVDC Light. HVDC Light is a relatively new technology for power transmission, but have before only been used for motor drives applications. The technology is based on VSC (Voltage Source Converter) that uses a technique called PWM (Pulse Width Modulation). There are a lot of PWM patterns that have been examined, but not in the field of power transmission where ABB Power Systems is working. The different PWM patterns can be used for reducing switching losses or harmonics, that can cause the need of external filters to decrease or increase. The purpose of this report is to give a general picture of the system that generates the PWM patterns. The report describes some main components in the system. T he thesis also present amplitude spectrum from various PWM patterns - generated by signals that have been pulse width modulated with a triangle- shaped wave. By showing the frequency-content, the decisions are eased for the engineers and technicians that are working with this kind of questions. An analysis of different PWM patterns have been done. The kind of reference waves that generate the PWM patterns are called Dead Band PWM and Modified SPWM. Comparisons have been done for Dead Band PWM, between harmonics and the width of Dead Band. Comparisons have been done for Modified SPWM, between: 1. fundamental frequency and modulation index. 2. different Modified SPWM and their harmonics.
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