- #Motor winding formula in hindi pdf generator#
- #Motor winding formula in hindi pdf full#
- #Motor winding formula in hindi pdf series#
That is, for a 10 A load the generated voltage will have to be 205 V to give a terminal voltage of 200 V between points A and B.
#Motor winding formula in hindi pdf generator#
If the designed generated voltage of the generator in Figure 1 is 200 V, and the armature has a resistance of 0.5 Ω, then for every ampere of current being supplied by the armature there is an internal voltage drop of 0.5 V due to the armature resistance.įor every 2 A of load current, 1 V will be lost internally and if 200 V is required at the generator terminals then the generating section will have to generate a higher voltage in the windings. Figure 1 shows a DC shunt-connected generator separated into its various imaginary component parts, while the broken lines indicate actual components.įigure 1 Equivalent circuit of a shunt generator DC Generator Efficiencyįor analysis purposes it is usual to assume that all the armature resistance is concentrated into one component and not distributed throughout the windings. If the armature current is doubled, the copper loss becomes four times as great and four times as much heat is generated this heat has to be removed, usually by air circulation, which adds a further loss to the system. The power loss in copper conductors varies as the square of the current flowing ( P = I 2 R).Īt light loads, the small current flow means the copper loss is at a minimum. These two are the main electrical losses in a motor and are added to obtain the total electric power loss.
#Motor winding formula in hindi pdf full#
While the iron loss is almost constant from no load to full load, the copper loss varies considerably due to load current. Together the losses are wasted energy which should be reduced as much as possible, often by simple good maintenance.Ĭopper power losses are due to the resistance of electrical windings, while iron power losses are due to hysteresis and eddy currents in the iron core of the armature. In electrical machines the term ‘other losses’ comprises copper losses, iron losses, magnetic leakage and other lesser factors. Windage is present because of air resistance to rotating components, and in fans added to ensure forced circulation of air for cooling purposes. Friction is present in all rotating machinery. Interpoles nullify the quadrature axis armature flux.Losses in DC machines (motor and generator) include friction, windage and electrical losses. Each interpole is wound in such a way that its magnetic polarity is same as that of the main pole ahead of it.
#Motor winding formula in hindi pdf series#
Winding on the interpoles is connected in series with the armature. Interpoles:Interpoles are the small auxiliary poles placed between the main field poles. Compensating winding is connected in series with the armature winding in such a way that it carries the current in opposite direction. Such an additional winding is called as compensating winding and it is placed on the pole faces. Now, if we place another winding in close proximity of the armature winding and if it carries the same current but in the opposite direction as that of the armature current, then this will nullify the armature field.
Armature flux is produced due to the current flowing in armature conductors. But for large DC machines, compensating winding and interpoles are used to get rid of the ill effects of armature reaction.Ĭompensating winding: Now we know that the armature reaction is due to the presence of armature flux. Usually, no special efforts are taken for small machines (up to few kilowatts) to reduce the armature reaction. On the other hand, for a loaded dc motor, MNA will be shifted in the direction opposite to that of the rotation. So, due to armature reaction, it is hard to determine the exact position of the MNAįor a loaded dc generator, MNA will be shifted in the direction of the rotation. Brushes should be placed on the M.N.A., otherwise, it will lead to sparking at the surface of brushes. is perpendicular to the flux lines of main field flux). Armature reaction distorts the main flux, hence the position of M.N.A.In case of a dc generator, weakening of the main flux reduces the generated voltage. Armature reaction weakens the main flux.The adverse effects of armature reaction: This effect is called as armature reaction in DC machines. The armature flux superimposes with the main field flux and, hence, disturbs the main field flux (as shown in third figure the of above image). Now, when a DC machine is running, both the fluxes (flux due to the armature conductors and flux due to the field winding) will be present at a time.
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