Informatica Economic vol. 16, no. 1/2012
132
Building Database-Powered Mobile Applications
Paul POCATILU
Bucharest University of Economic Studies
ppaul@ase.ro
Almost all mobile applications use persistency for their data. A common way for complex
mobile a
Electrical Machines II
8
Prof. Krishna Vasudevan, Prof. G. Sridhara Rao, Prof. P. Sasidhara Rao
Speed control of Induction Machines
We have seen the speed torque characteristic of the machine. In the stable region of operation
in the motoring mode, the cu
Electrical Machines II
4
Prof. Krishna Vasudevan, Prof. G. Sridhara Rao, Prof. P. Sasidhara Rao
Construction
In actual practice, the three coils form three windings distributed over several slots. These
windings may be connected in star or delta and three
Electrical Machines II
9
Prof. Krishna Vasudevan, Prof. G. Sridhara Rao, Prof. P. Sasidhara Rao
Harmonics in Induction Machines
In attempting to understand the performance of an induction machine, we consider that the
air-gap ux wave is purely sinusoidal.
Electrical Machines II
7
Prof. Krishna Vasudevan, Prof. G. Sridhara Rao, Prof. P. Sasidhara Rao
Deducing the machine performance.
From the equivalent circuit, many aspects of the steady state behavior of the machine can be
deduced. We will begin by lookin
Electrical Machines II
3
Prof. Krishna Vasudevan, Prof. G. Sridhara Rao, Prof. P. Sasidhara Rao
Principles of Torque Production
In the earlier section, we saw how a rotating ux is produced. Now let us consider a rotor,
which is placed in this eld. Let the
Electrical Machines II
2
Prof. Krishna Vasudevan, Prof. G. Sridhara Rao, Prof. P. Sasidhara Rao
The Rotating Magnetic Field
The principle of operation of the induction machine is based on the generation of a rotating
magnetic eld. Let us understand this i
Electrical Machines II
Prof. Krishna Vasudevan, Prof. G. Sridhara Rao, Prof. P. Sasidhara Rao
Induction Machines
1
Introduction
The induction machine was invented by NIKOLA TESLA in 1888. Right from its inception its ease of manufacture and its robustness
Electrical Machines II
6
Prof. Krishna Vasudevan, Prof. G. Sridhara Rao, Prof. P. Sasidhara Rao
Determination of Circuit Parameters
In order to nd values for the various elements of the equivalent circuit, tests must be
conducted on a particular machine,
Electrical Machines II
5
Prof. Krishna Vasudevan, Prof. G. Sridhara Rao, Prof. P. Sasidhara Rao
Equivalent Circuit
It is often required to make quantitative predictions about the behavior of the induction
machine, under various operating conditions. For t
Electrical Machines-I
Prof. Dr Debaprasad Kastha
Department of Electrical Engineering
Indian Institute of Technology, Kharagpur
Lecture - 24
Armature Reaction
(Refer Slide Time: 00:29)
Let us see, an example of how to calculate the induced voltage in a dc