Results 261 to 270 of about 69,679 (307)

Performance of DC Machines

2015
In this chapter, the authors provide an overview of the issues related to losses and efficiency of D.C. machines. Speed control is then discussed. Solid state speed control is discussed afterwards. Speed Control using thyirstors. After finishing the discussion on speed control, the authors discuss braking DC motor, regenerative braking, dynamic braking,
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Measurement of Inductance of DC Machines

IEEE Transactions on Power Apparatus and Systems, 1979
Information is presented showing the general suitability of present measurement techniques outlined in IEEE Std 113-Standard Test Code for Direct Current Machines. The significance of machine parameters so determined is shown to be compatible with the most common usage of the application data. Revisions of the present test procedures are proposed.
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GTO thyristor commutation of DC machine

Conference Record of the IEEE Industry Applications Society Annual Meeting, 2003
The authors review the fundamental mechanism by which rotating electrical machines develop torque and draw conclusions as to which configuration offers inherent advantages in this regard. Development of a DC machine with a continuous armature winding where gate turn-off (GTO) thyristors replace the traditional copper-segment-carbon-brush commutator is ...
C.B. Gray, A. Ghaffary, A.M.H. Karim
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Converters and DC-Machine Control

1995
It was found from the transfer-functions of the separately excited DC-machine that modification of the torque needs control of the armature current and modification of the speed requires control of either the armature voltage or the excitation voltage. Changing the speed-torque characteristic using series resistors is possible in principle but leads to
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DC machines

2023
M.J. Melfi, S.D. Umans
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A Mathematical Model of a DC Machine

2005
This research aims to determine how a mathematical model may predict the effects of a shorted and/or opened armature coil on a d-c machine. A mathematical model and a simulating computer were developed for a particular 0.375 kW d-c machine under both healthy and faulty conditions.\ \ The model was based on the coupled-coil theory, with a set of first ...
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Separately Excited DC Machine

1985
Direct current (DC) motors have been dominating the field of adjustable speed drives for over a century; they are still the most common choice if a controlled electrical drive operating over a wide speed range is specified. This is due to their excellent operational properties and control characteristics; the only essential disadvantage is the ...
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Evaluation of losses in DC machines - A statistical approach

IEEE Transactions on Industry Applications, 1990
The power ratings of the drive systems used in cyclic duty applications such as flying-die and cut-to-length shears are dictated by the thermal considerations associated with the losses produced by the machine during an operation cycle and the specified production rate.
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Theory of Brushless dc Machines

2009
This chapter contains sections titled: Introduction Voltage and Torque Equations in Machine Variables Voltage and Torque Equations in Rotor Reference-Frame Variables Analysis of Steady-State Operation Dynamic Performance References ...
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Modeling and Supplying DC Machines

2012
In this chapter, mathematical model is developed for DC machines with excitation windings and DC machines with permanent magnet excitation. The block diagram of the model is used to provide a brief introduction to the torque control. Steady-state equivalent circuits are derived and explained for armature and excitation windings. These circuits are used
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