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

Determine the power delivered to the delta-connected load, Q. A balanced de...

Q. A balanced delta-connected load with a per-phase impedance of 30+j10  is connected in parallel with a balanced wye-connected load with a per phase impedance of 40-j10 . This l

Circuit analysis, what is quality factor in term circuit analysis

what is quality factor in term circuit analysis

Show the conditions necessary for sustained oscillation, The conditions nec...

The conditions necessary for sustained oscillation can be summarized as follows: 1. There should be a positive feedback. 2. The loop gain of the circuit must be equal to or g

Determine the maximum value of the voltage, Q. Three waveforms seen on an o...

Q. Three waveforms seen on an oscilloscope are shown in Figure. If the horizontal scale is set to 50 ms per division (500 ms for the entire screen width), and the vertical scale is

Explain ferroelectricity, Explain ferroelectricity. Ferroelectricity: ...

Explain ferroelectricity. Ferroelectricity: - Materials of ferroelectric have a high dielectric constant that is non-linear that is, this depends to a considerable extent on t

Write short note on a negative clamper, Q. Write short note on a negative c...

Q. Write short note on a negative clamper ?   A circuit which places the negative peak of a signal at a desired level is known as a negative clamper (1). During the

Trivalent impurity to a semiconductor, Addition of trivalent impurity to a ...

Addition of trivalent impurity to a semiconductor creates many (A) Holes. (B) Free electrons. (C) Valance electrons. (D) Bound electrons. Ans: Addition o

Sign flag - sub subtract instruction , Sign flag Since D 7  bit in ...

Sign flag Since D 7  bit in the  results is 0sign flag is reset. This also  shown that the results is positive.

Asynchronous message passing and synchronous-message passing, Question: ...

Question: a) Differentiate between Asynchronous message passing and Synchronous-message passing. b) If keyboards are the predominant means of interface to human input, the

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