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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the 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.
1

A method for concurrently optimising the weight and response of wound field direct current motors.

El Aker, Mounzer Nizar January 2004 (has links)
Title page, abstract and table of contents only. The complete thesis in print form is available from the University of Adelaide Library. / Compact, lightweight and responsive direct current (DC) motors are desirable in industries requiring precise control operations such as those using robotic and micro-robotic devices. Permanent magnet (PM) motors have been used exclusively in these industries, in recent years, because they meet these requirements. However, their speed range and output torque are limited compared to wound field direct current (WF DC) motors and this renders them far less effective than WF DC motors in terms of handling load disturbances. So far, only one study by Reyer and Papalambros (1999) has investigated a method for concurrently optimising the weight and response of WF DC motors with, in this case, proportional, integral and derivative (PID) controllers. However, the documentation provided in their study suggests that their optimised WF motor was defective in terms of efficiency, speed and shape. The aim of the present study was to develop Reyer and Papalambros's method in a way that overcomes the problems that arose. To do this, first an investigation into Reyer and Papalambros's mathematical model was conducted, and their equality and inequality equations have been modified. Second, their optimisation model has been represented by its transfer functions. Third, their model's parameters and variables have been reconsidered. Finally, the WF motor/controller system was discretely optimised. Following these developments, the new method was used to optimise the weight and response of a motor/controller system capable of driving a 6 Nm torque in MATLAB to illustrate the developed method and compare its outcome with that achieved by Reyer and Papalambros in 1999. The comparison indicated that the method developed here is superior and the weight and response of the system optimised by this current study outperforms the one developed by Reyer and Papalambros. To confirm the validity of the developed weight optimisation model, the weight of a 50 watt WF DC prototype motor was partially optimised experimentally. This resulted in the weight of this motor being successfully reduced. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1104468 / Thesis (M.Eng.Sc.) -- University of Adelaide, School of Mechanical Engineering, 2004

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