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

Harmonics, how harmonics shows effect on power systems?

how harmonics shows effect on power systems?

Determine the line current-total apparent power, A balanced three phase, fo...

A balanced three phase, four wire, WYE connect load consisting of per phase resistenance of A ohms and inductive reactance of D ohms/phase is connected to a B000 V three phase sour

Bipolar junction transistor, Bipolar junction transistor: Transistors ...

Bipolar junction transistor: Transistors are so named as they conduct via using both majority and minority carriers. The bipolar junction transistor that is abbreviated as BJT

memory to register , Memory  to Register This  instruction is used to...

Memory  to Register This  instruction is used to copy the contents of a memory  locations whose  address is specified by the HL register  pair to any register. Before  using th

2365 - 305 task a, List four sources of information which are essential to ...

List four sources of information which are essential to the designer of this electrical installation.

Basic principles of electrical engineering, What is ideal and real sources?...

What is ideal and real sources? Source conversion? Nodal voltage method for d.c circuit?

Explain protected mode addressing, Explain protected mode addressing. ...

Explain protected mode addressing. This addressing permits access to data and programs located as the first 1M byte of memory, with in the first 1M byte of memory. Addressing

Evaluate supply and the supply power factor, Q. Two balanced, three-phase, ...

Q. Two balanced, three-phase, wye-connected loads are in parallel across a balanced three-phase supply. Load 1 draws a current of 20 A at 0.8 power factor leading, and load 2 draws

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