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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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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VANOS (Variable Nockenwellen Steuerung) is an automobile variable valve timing technology developed by BMW in close collaboration with Continental Teves. VANOS varies the duration of the intake valves by moving the position of the camshafts in relation to the drive gear. This movement varies from 6degrees of advanced to 6degrees of retarded camshaft timing. BMW recently began offering 'double' VANOS, which operates on the exhaust camshaft as well, on a number of its cars. ....etc

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Valve timing is the regulation of the points in the combustion cycle, at which the valves are set to open and close. Since the valves require a finite period of time in which to open or close without abruptness, a slight lead-time is always necessary for proper operation. The design of the valve-operating cam provides for the smooth transition from one position to the other, while the cam setting determines the timing of the valve.

In a typical four-stroke engine, the inlet valve is set to open before TDC (top dead centre), towards the end o ....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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Variable Length Intake Manifold (VLIM)

Variable Length Intake Manifold (VLIM) is an automobile engine manifold technology. As the name implies, VLIM can vary the length of the intake tract in order to optimize power and torque, as well as provide better fuel efficiency.

There are two main effects of variable intake geometry:

* Swirl - Variable geometry can create a beneficial air swirl pattern in the combustion chamber. The swirls help distribute the fuel and form a homogeneous air-fuel mixt ....etc

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Variable Length Intake Manifold (VLIM) is an automobile engine manifold technology. As the name implies, VLIM can vary the length of the intake tract in order to optimize power and torque, as well as provide better fuel efficiency.

There are two main effects of variable intake geometry:

Swirl - Variable geometry can create a beneficial air swirl pattern in the combustion chamber. The swirls help distribute the fuel and form a homogeneous air-fuel mixture which ignites without engine knocking.

At low rpm, the speed of the airflow is inc ....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 stop go traffic condition has become synonymous with driving in our big cities. In such a case will automatics transmission make sense to the Indian customer. Well the Indians haven?t taken to automatics like fish to water. The reason being conventional automatics always consume slightly more fuel than manual transmission and the lack of sophisticated automatics.


With the increase in traffic conjunction in the cities stop go traffic has become a big hassle with constant gear changing. In such a situation CVTs or continuous variable ....etc

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Definition

After more than a century of research and development, the internal combustion (IC) engine is nearing both perfection and obsolescence: engineers continue to explore the outer limits of IC efficiency and performance, but advancements in fuel economy and emissions have effectively stalled. While many IC vehicles meet Low Emissions Vehicle standards, these will give way to new, stricter government regulations in the very near future. With limited room for improvement, automobile manufacturers have begun full-scale development of alt ....etc

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