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

Magnetic contactor, how to wire a three phase contactor to become a single ...

how to wire a three phase contactor to become a single phase contactor?

Explain the drain characteristics of jfet with external bias, Q. Explain th...

Q. Explain the drain characteristics of JFET with external bias? It gives relation between Id and Vds for different values of Vgs.(which is called the running variable). The ab

Compute the maximum electromagnetic power, Q. A four-pole dc machine with 7...

Q. A four-pole dc machine with 728 active conductors and 30mWb flux per pole runs at 1800 r/min. (a) If the armature winding is lap wound, find the voltage induced in the armatu

Explain the effect of magnetic field on superconductors, Explain supercondu...

Explain superconductivity and explain the effect of magnetic field on superconductors. Various metals become superconducting below a temperature that is the characteristic of t

Object oriented programming by robert lafore 4th edition sol, Ask quobject ...

Ask quobject oriented programming by robert lafore 4th edition solutionestion #Minimum 100 words accepted#

Explain briefly programmable interval timer 8254, Explain with proper diagr...

Explain with proper diagram all the six modes of operation of programmable interval timer 8254. Mode 0: The output in mode 0 is initially low, and will stay low for the perio

Pn junction, the depletion layer in the pn junction is caused by

the depletion layer in the pn junction is caused by

Effect of frequency - stepper motor , Effect of Frequency a.From equa...

Effect of Frequency a.From equation for given  H p and μ P v α √f b.From  equation the depth of penetration for a given  material δ α 1/ √f c.From  equation hyst

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