Direct digital control of D.C. machines

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dc.contributor.advisorMcLaren, S Gen_ZA
dc.contributor.authorVon Zwiklitz, Aubrey Paulen_ZA
dc.date.accessioned2016-03-14T07:02:22Z
dc.date.available2016-03-14T07:02:22Z
dc.date.issued1972en_ZA
dc.description.abstractThis thesis set out to improve on previous methods of digital control of a three phase fully controlled thyristor bridge, using phase control of the thyristors, and to use this bridge for the purpose of controlling the speed of a separately excited D. C. machine, under the supervision of a small digital computer. Interfacing equipment for this purpose was designed and built. Various methods of speed detection were considered, and a simple digital tachometer designed and built. This tachometer was able to feed a digital number, related to the speed of the machine, to the computer, and was accurate to better than 1%. A direct digital control system was then implemented. The behaviour of the system was first studied under open loop conditions in order to determine the parameters of the system, and to discover any shortcomings in it. The behaviour of the closed loop system was then studied, using z-transform analysis, at sampling rates of from twice to eight times the natural frequency of the machine. Initially, the computer was used as an integral controller. The behaviour of the mathematical model was compared to that of the actual system, and the correlation found to be very good. The control system was then compensated, using compensation routines based on the z-transform analysis, and the behaviour of various compensated systems studied at sampling rates varying from 0,4 to 1 second. Again, the actual system response was found to correspond closely to the designed behaviour. Finally, a dual-machine control system, on a time sharing basis, was implemented, and a degree of interrelation between the speeds of the two machines introduced. The control algorithms developed were able to provide speed control to better than l% accuracy, with a 5% or less overshoot in the step response, a delay of one sampling period but no overshoot in the ramp response, and satisfactory behaviour under load transient conditions. The time, and memory, utilization was such that such algorithms could be extended to the control of several machines, using the single computer, if sufficient input and output facilities were available.en_ZA
dc.identifier.apacitationVon Zwiklitz, A. P. (1972). <i>Direct digital control of D.C. machines</i>. (Thesis). University of Cape Town ,Faculty of Engineering & the Built Environment ,Department of Electrical Engineering. Retrieved from http://hdl.handle.net/11427/17669en_ZA
dc.identifier.chicagocitationVon Zwiklitz, Aubrey Paul. <i>"Direct digital control of D.C. machines."</i> Thesis., University of Cape Town ,Faculty of Engineering & the Built Environment ,Department of Electrical Engineering, 1972. http://hdl.handle.net/11427/17669en_ZA
dc.identifier.citationVon Zwiklitz, A. 1972. Direct digital control of D.C. machines. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Von Zwiklitz, Aubrey Paul AB - This thesis set out to improve on previous methods of digital control of a three phase fully controlled thyristor bridge, using phase control of the thyristors, and to use this bridge for the purpose of controlling the speed of a separately excited D. C. machine, under the supervision of a small digital computer. Interfacing equipment for this purpose was designed and built. Various methods of speed detection were considered, and a simple digital tachometer designed and built. This tachometer was able to feed a digital number, related to the speed of the machine, to the computer, and was accurate to better than 1%. A direct digital control system was then implemented. The behaviour of the system was first studied under open loop conditions in order to determine the parameters of the system, and to discover any shortcomings in it. The behaviour of the closed loop system was then studied, using z-transform analysis, at sampling rates of from twice to eight times the natural frequency of the machine. Initially, the computer was used as an integral controller. The behaviour of the mathematical model was compared to that of the actual system, and the correlation found to be very good. The control system was then compensated, using compensation routines based on the z-transform analysis, and the behaviour of various compensated systems studied at sampling rates varying from 0,4 to 1 second. Again, the actual system response was found to correspond closely to the designed behaviour. Finally, a dual-machine control system, on a time sharing basis, was implemented, and a degree of interrelation between the speeds of the two machines introduced. The control algorithms developed were able to provide speed control to better than l% accuracy, with a 5% or less overshoot in the step response, a delay of one sampling period but no overshoot in the ramp response, and satisfactory behaviour under load transient conditions. The time, and memory, utilization was such that such algorithms could be extended to the control of several machines, using the single computer, if sufficient input and output facilities were available. DA - 1972 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 1972 T1 - Direct digital control of D.C. machines TI - Direct digital control of D.C. machines UR - http://hdl.handle.net/11427/17669 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/17669
dc.identifier.vancouvercitationVon Zwiklitz AP. Direct digital control of D.C. machines. [Thesis]. University of Cape Town ,Faculty of Engineering & the Built Environment ,Department of Electrical Engineering, 1972 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/17669en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentDepartment of Electrical Engineeringen_ZA
dc.publisher.facultyFaculty of Engineering and the Built Environment
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherElectrical Engineeringen_ZA
dc.subject.otherElectronic Engineeringen_ZA
dc.titleDirect digital control of D.C. machinesen_ZA
dc.typeMaster Thesis
dc.type.qualificationlevelMasters
dc.type.qualificationnameMSc (Eng)en_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
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