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

Fourier transform for the function, The far-field pattern of an antenna can...

The far-field pattern of an antenna can be modeled as the two dimensional Fourier Transform of the aperture. 1. Determine the 2D Fourier Transform for the function

DC machine, importance of dummy coils and equalizer connections

importance of dummy coils and equalizer connections

Determine the performance of the circuits, With the development of cheap an...

With the development of cheap and reliable operational amplifiers the need to design amplifier circuits has disappeared. However it is still necessary to utilise these devices in a

Digital logic circuits, . In successive-approximation A/D converter, offset...

. In successive-approximation A/D converter, offset voltage equal to 1/2LSB is added to theD/A converter’s output. This is done to

Rlc circuit, how started the use of complex variables in circuit analysis f...

how started the use of complex variables in circuit analysis for the first time.

Absorption of radiation and stimulated emission, Absorption of radiation ...

Absorption of radiation If an atom is initially in a lower state 1, it can rise to a higher stare 2 by absorbing a quantum of radiation. Photon of frequency v where E 1 and E

What are the various types of amplifiers, Q. What are the various types of ...

Q. What are the various types of amplifiers? Amplifiers can be classified as follows: (a) Based on the transistor configuration 1. Common emitter amplifier 2. Common c

Evaluate the efficiency of embedded systems, Questions: a) One common ...

Questions: a) One common characteristic of Embedded Systems is that they need to be dependable. Name and describe any three aspects which encompass dependability. b) Name

Define the general purpose embedded system, Define the general purpose embe...

Define the general purpose embedded system. a. General purpose microprocessor For illustration, Intel 80x86, Motorola 68HCxxx or Sparc b. Embedded general purpose process

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