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

What do you mean by frequency response, Q. What do you mean by Frequency re...

Q. What do you mean by Frequency response? Now let us examine the response of a circuit to a sinusoidal source, called an oscillator, whose frequency can be varied.Known as the

Piezo crystal osillator, whether piezo crystal and quazt crystal oscillator...

whether piezo crystal and quazt crystal oscillator are same?

Radio over Fiber, I need to get a summary for a radio over fiber paper that...

I need to get a summary for a radio over fiber paper that I have , the summary need to be on the following format: abstract, introduction,methodology,results, conclusion and refere

Impedance heating system, Under what circumstances is individual circuit pr...

Under what circumstances is individual circuit protection for a lighting and applications panel board not required? What is the purpose of guarding runway contact conductors and

Explain output ce characteristics, Q. Explain output CE characteristics? ...

Q. Explain output CE characteristics? 1. In the active region ic increases slowly as Vce increases. The slope of the curved is greater than the CB output characteristics. In co

What is positive clipper, Q. What is positive clipper? Give 2 types of its ...

Q. What is positive clipper? Give 2 types of its applications ? In the series positive clipper, when the input voltage is positive, the diode does not conduct and acts an open

Explain the and gates - microprocessor, Explain the AND GATES - Microproces...

Explain the AND GATES - Microprocessor? The AND GATE has a logic 1 or high output if the entire inputs are high. The boolean and symbol expression for a 3-input AND gate is sho

Oscilloscope probe compensation, Q.   what is oscilloscope probe compensati...

Q.   what is oscilloscope probe compensation and how is it adjusted?  What effects are noted when the compensation is not correctly adjustment? Direct Probe: This probe  is

Basic specifications of a ujt, The very basic specifications of a UJT are: ...

The very basic specifications of a UJT are: Vbb(max) - The maximum interbase voltage that can be applied to the UJT (b) Rbb-the interbase resistance of the UJT (c) n - 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