VARIABLE SPEED DC MOTOR DRIVE


DC MOTOR THEORY:
Inducing a Force on a Conductor.
There are two conditions which are necessary to produce a force on a conductor:
i. The conductor must be carrying current.
ii. The conductor must be within a magnetic field.
When these two conditions exist, a force will be applied to the conductor, which
will attempt to move the conductor in a direction perpendicular to the magnetic
field. This is the basic theory by which a ....etc

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SPEED CONTROL OF SYNCHRONOUS MOTOR BY USING VARIABLE FREQUENCY DRIVES



ABSTRACT :

A novel open-loop speed control method for induction motors that provides high output torque and nearly zero steady-state speed error at any frequency is presented. The control scheme is based on the popular constant volts per hertz (V/f) method using low-cost open-loop current sensors. Only stator current measurements are needed to compensate for both stator resista ....etc

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i need this pdf file can you please make it available for me. thanx ....etc

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The History and State of the Art of
Variable-Speed wind Turbine
Technology

ABSTRACT
Early wind turbines used for performing mechanical work (pumping, grinding and cutting) optimized aerodynamics by being allowed to run at variable speed. Some of the earliest DC electric wind turbines were allowed to run at variable speed. With the advent of gridconnected AC turbines, rotational speeds were limited in order to control the wind turbine AC frequency output to equal the grid frequency. With the advent of se ....etc

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A variable-speed controller, for an existing 225 kW fixed-speed wind power generator, is presented in this paper. A sensorless direct torque control algorithm-based controller is proposed for the squirrel-cage induction generator. Generator torque reference is derived based on sensorless maximum power tracking mode algorithm, up to the base speed of the generator. A three-phase front-end converter is used here to deliver the generated power to the grid with unity-power-factor operation at all wind speeds. This algorithm is based on direct activ ....etc

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Every kW of energy saved is as good as same amount of energy generated. Such is the scarcity of energy in India. Energy can be saved by using Variable Speed Drives (VSD) for applications like Pumps and Fans. Employing conventional techniques, which uses a motor running at full speed and flow pressure being created by throttle valve, a lot of energy is wasted due to electric, thermal and mechanical losses. By replacing conventional arrangement with AC drives, tremendous amount of energy can be saved. However, traditional approach to flow control ....etc

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ppt related to induction motor drive using seven level multi level inverter for energy saving in variable torque load applications
PPT RELATED TO INDUCTION MOTOR DRIVE USING SEVEN LEVEL MULTI LEVEL INVETER FOR ENERGY SAVING IN VARIABLE TORQUE LOAD APPLICATIONS ....etc

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Variable Voltage And Variable Frequency drives

Presented By:
P.NATARAJU S.E.V.S.RAGHU VARMA
3rd year E.E.E. 3rd year E.E.E.

Abstract:-
Our varying industrial needs demand more precise control of the outputs of our basic electrical prime movers i.e, THE MOTORS. Basically dc motors are easy to control compared to their ac counter parts, but they have their own limitations with increase in capacity. Conversely ac motors in particular squirrel cag ....etc

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This article is presented by:
O. Barambones∗, A.J. Garrido∗, F.J. Maseda∗ and P. Alkorta†Speed Sensorless Vector Control of Induction Motors Based on
Robust Adaptive Variable Structure Control Law

ABSTRACT
A novel sensorless adaptive robust control law is proposed to improve the trajectory tracking performance of induction motors. The proposed design employs the so called vector (or field oriented) control theory for the induction motor drives and the designed ....etc

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SPEED CONTROL OF SYNCHRONOUS MOTOR BY USING VARIABLE FREQUENCY DRIVES



ABSTRACT :

A novel open-loop speed control method for induction motors that provides high output torque and nearly zero steady-state speed error at any frequency is presented. The control scheme is based on the popular constant volts per hertz (V/f) method using low-cost open-loop current sensors. Only stator current measurements are needed to compensate for both stator resistance d ....etc

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