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

Air gaps, What is the main thing to look for in calculations of air gaps?

What is the main thing to look for in calculations of air gaps?

Network analysis, expain how to do proper initial approximatio for the give...

expain how to do proper initial approximatio for the given cct....... by a example

What is pinch-off voltage, Q. What is Pinch - off voltage?  The reverse...

Q. What is Pinch - off voltage?  The reverse bias is relatively large near the source. As a result, the depletion region intrudes into the channel near the drain, and the effec

Measure phase angle by using an oscilloscope, 1. Introduction : ...

1. Introduction : Theory:  Phase angle is defined as the number of degrees separating two sine waves of the same frequency. The Phase shift is defined as any change t

Ac motors, AC Motors DC motors that have their magnetic fields produce...

AC Motors DC motors that have their magnetic fields produced by coils as described earlier can, in principle,  be powered from AC as well, since if the applied voltage reverse

Give the properties and application of glass, Give the properties and appli...

Give the properties and application of glass. Glass - It is an inorganic material made by the fusion of various metallic oxides. The properties of glass are as - Glass is

Moving coil transducers, Note transducers  convert a physical quantity from...

Note transducers  convert a physical quantity from one  form to another.  The case below illustrates a typical moving coil meter   that   converts   a   current into a mechanical a

Introduction to electronics, Explain the difference between a microprocesso...

Explain the difference between a microprocessor and an embedded microcontroller

Electric scooter, Hi there i need help with design battery charger for elec...

Hi there i need help with design battery charger for electric scooter 24v battery. i have to design sechmatic diagram and PCB for it. using Altuim design software many thanks 006

Determine the peak frequency deviation, If an FM signal is given by s FM (t...

If an FM signal is given by s FM (t) = 100 cos [2πf c t +100 m(τ ) dτ ] and m(t) is given in figure, sketch the instantaneous frequency as a function of time and determine the pea

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