The three-phase alternator, Electrical Engineering

Assignment Help:

The Three-phase alternator

In this case, three separate sets of coils are wound on the stator and connected to produce three separate outputs. Because of the physical displacement of the coils around the stator, the outputs will have different phases with respect to each other. Three-phase systems are common even when DC outputs are required (e.g. electric alternators to charge a car battery) because of the torque reaction problem mentioned above. The AC output is rectified with a set of six diodes mounted in a single pack (two diodes are needed to rectify each phase).

A  two-pole, three-phase alternator is shown in the diagram below. Stator coils AB belong to phase 1, coils CD to phase 2 and coils EF to phase 3. Each pair of coils are connected  in series and their outputs add (e.g. A and B are connected in series to  produce  phase  1  output).  Notice  it  is two-pole because there are only two poles (i.e. one pole pair) on the rotor. The frequency of each phase output is therefore equal to the rotational speed of the rotor.

1357_The Three-phase alternator.png

 

 

 

Unlike the single-phase  alternator, it turns out  that  the  torque  required  to  drive  a three-phase alternator is constant, with no pulsating component. This is an important advantage.The figure below shows the arrangement for   a     multipole   three-phase   alternator. Again, coils A&B, C&D and E&F are connected in series to three differnet outputs, each with a phase shift  of 120° apart (because of the physical arrangement of the coils on the stator).

1646_Three-phase alternator.png

 

 


Related Discussions:- The three-phase alternator

Illustrate gray code, (a) In the so-called folded binary code of 4 bits, th...

(a) In the so-called folded binary code of 4 bits, the left most digit represents the sign of an analog signal's quantized samples (with 0 for negative and 1 for positive), and the

Calculate the rms voltage generated in each phase, Q. Consider an elementar...

Q. Consider an elementary three-phase, four-pole alternator with a wye-connected armature winding, consisting of full-pitch concentrated coils.  Each phase coil has three turns,

#need digital related, Is there any electronics related papers like digital...

Is there any electronics related papers like digital for free download

Explain magnetostriction, Explain Magnetostriction. Magnetostriction: I...

Explain Magnetostriction. Magnetostriction: If ferromagnetic materials are magnetized a small change of dimensions of the material obtains place. There is a small extension alo

Followings are some disadvantage , Followings  are some  disadvantage ...

Followings  are some  disadvantage a.   Higher latching and holding  current b.Higher  on state  voltage  drop and power  losses c.Higher  gate  current d.Higher  gat

Perfect gases avogadro''s hypothesis, Equal volumes of all gases contain th...

Equal volumes of all gases contain the samenumber of molecules when the volumes are measured at the same p and T. Therefore for a given volume at the same p and T, with the same

Transformer, how back emf is produced in transformer?

how back emf is produced in transformer?

., ABOUT ASSIGNMENT ON MAGNETIC INDUCTION NEAR A LONG WIRE

ABOUT ASSIGNMENT ON MAGNETIC INDUCTION NEAR A LONG WIRE

Explain the fixed bias circuit, Q. Explain the fixed bias circuit?     ...

Q. Explain the fixed bias circuit?           The Fig refers to the common emitter collector characteristics and the ac and dc load lines.The Fig shows the points Q 1 and Q 2

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd