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Design of an adaptive digital controller for an SCR driven DC motorLadwig, Lee Roger, January 1976 (has links)
Thesis (M.S.)--University of Wisconsin--Madison. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaf 92).
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The influence of motor parameter deviations in feedforward field orientation drive systemsNordin, Kamarudin Bin. January 1984 (has links)
Thesis (M.S.)--University of Wisconsin--Madison, 1984. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 87-88).
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Study of a direct current (D.C.) servo systemṢamdānī, Iftiḵẖār Aḥmad Nayyar January 1980 (has links)
No description available.
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An analytical study of back-to-back HVDC link in weak AC systems /Hellal, Abdelhafid. January 1986 (has links)
No description available.
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Nonlinear modelling of three phase multi limb transformersWu, Zhengqiu January 1998 (has links)
No description available.
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Series operation of thyristors in HVDC convertersNaik, K. R. January 1970 (has links)
High voltage direct current. (hvdc) transmission of electrical paver has been made possible with the recent advent of multi-anode mercury arc valves with grading electrodes. However, mercury are valves do suffer from random phenomena such as arcback, which requires special bracing for the converter transformer. In addition, mercury arc valves need considerable auxiliaries, including cooling and vacuum plants. Research and development directed towards the improvement in the voltage and current capabilities of thyristors are yielding encouraging results. In contrast to mercury arc valves, thyristors do not suffer from random phenomena and require minim auxiliaries. Considering these advantages, thyristors offer a viable alternative to mercury arc valves for hvdc converters. The comparatively low ratings of thyristors necessitate series and parallel connection of thyristors in order to construct a valve of sufficient rating for hvdc operation. The design of thyristor valve should ensure even distribution of voltage and current among all thyristors of the valve, during all operating conditions. To achieve this objective transmission of the firing signal to the gate of each thyristors should have good coherence. The thesis examines design aspects, and considers the different methods of firing both theoretically and practically. Finally, the design and subsequent experimental results of the prototype thyristors valve rated at 10kv and 10A are also included.
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An analytical study of back-to-back HVDC link in weak AC systems /Hellal, Abdelhafid January 1986 (has links)
No description available.
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Speed Control of DC Shunt Motor for Electric Car UseShahi, Mahmood 01 April 1980 (has links) (PDF)
This report describes the speed characteristic and various methods of speed control of DC shunt (separately excited) motors, especially for application in electrical vehicles. The basic behavior of the DC motor is discussed, along with traditional and modern techniques of speed control. As an example, a speed controller for a shunt motor (built and tested by the author) is discussed. Two types of speed controllers for electric cars are discussed, and the performance results for an experimental electric car are presented. Finally, a design for a 24 HP car motor controller using both armature and field control was simulated on a smaller scale in the laboratory.
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Prediction of DC current flow between the Otjiwarongo and Katima Mulilo regions, NamibiaShare, Pieter-Ewald 14 February 2013 (has links)
As an additional opportunistic component to the Southern African Mag-
netotelluric Experiment (SAMTEX), audio-magnetotelluric (AMT) data were
acquired during the most recent phase of the experiment (Phase IV) to inves-
tigate the local-scale conductivity substructure in the Otjiwarongo and Ka-
tima Mulilo regions (Namibia), as to aid in the installation of high-voltage
direct current (HVDC) earth electrodes that has since taken place. Both
of the AMT surveys are situated close to the edge of the orogenic Neo-
Proterozoic Damara Mobile Belt (DMB). Previous studies all point to the
existence of a highly conductive mid-crustal zone which correlates well with
the spatial location of the DMB. Two-dimensional (2D) inverse modelling
of the Otjiwarongo AMT data con rms the existence of the high conductive
zone at mid-crustal depths (10-15 km). The high conductivity of the DMB
is explained by the presence of interconnected graphite in the marble units
present. The Katima Mulilo inversion results are characterized by a con-
ductive upper crustal layer that does not form part of the DMB conductive
belt. It is deduced that at the uppermost subsurface Kalahari sediments are
responsible for the high conductivity observed while at greater depth it is
due to ironstone within the Ghanzi Group. In contrast to the conductive
DMB, the lithospheric structure of the neighbouring Archaean cratons, the
Congo and Kalahari, are generally found to be electrically resistive. There-
fore, it is hypothesized that ground return current, if present, will
ow along
a path between the Otjiwarongo and Katima Mulilo regions that lies either
exclusively, or almost entirely within the DMB. The hypothesis is tested
by inputting a three dimensional (3D) conductivity model (calculated using
available magnetotelluric (MT) data and geological information) of the re-
gion into a DC resistivity forward modelling code. Forward modelling shows
that the return current is only con ned to, and follows regional trends char-
acteristic of, the conductive DMB for approximately 200-300 km away from
the injection point, after which there is no preferential flow.
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Sensorless starting of a brushless D.C. motorGhosh, Ramit 22 June 2010 (has links)
Permanent magnet brushless DC motors that have found wide application in high performance servo drives need absolute rotor position sensors. However, the cost of the position sensor limits the use of brush less DC motors for low performance applications such as automotive and home appliances. A sensorless starting scheme for brushless DC motors is studied in this thesis. A hardware implementation of the starting scheme has been instrumented. The modeling and simulation of the sensorless starting performance of brushless DC motors have been accomplished to gain the insight into the process. The experimental results confirm the theoretical prediction that the permanent magnet brush less DC motor can be started without a position sensor. The experimental setup with individual subsystems are described in detail. / Master of Science
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