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

Explain sahf instructions in 8086 family, Explain SAHF instructions in 80...

Explain SAHF instructions in 8086 family with example and their effect on flag. SAHF: Store AH register in flag register, this is an instruction utilized to store the data i

Magnetism, What is mgnomotive force

What is mgnomotive force

Scr, What is finger voltage in a scr?

What is finger voltage in a scr?

Find the exponential form of the fourier series, Q. Find the exponential fo...

Q. Find the exponential form of the Fourier series of the periodic signal given in Figure. Also determine the resulting series if T = 2τ .

Explain the construction of a mosfet, Explain the construction of a MOSFET....

Explain the construction of a MOSFET. Draw the symbols and diagrams of both P-channel and N-channel MOSFET. As JFET and MOSFET also have source, drain and gate. Its gate is ins

Signals and spectral analysis, Q. Signals and spectral analysis? Figure...

Q. Signals and spectral analysis? Figure shows the functional block diagram of a signal-processing system. The information source may be a speech (voice), an image (picture), o

With the help of the structures explain lcd, Q. With the help of the struct...

Q. With the help of the structures explain LCD. A liquid crystal display (LCD) is a thin, flat display device made up of any number of color or monochrome pixels arrayed in fro

Partial indicators method, Partial Indicators Method The partial indic...

Partial Indicators Method The partial indicators technique consists of calculating various measures of the financial, operating, commercial, and quality of a business's perfor

Modern AC Generators, What are the advantages of modern ac generators and I...

What are the advantages of modern ac generators and Integrated Drive Generators? There are two questions here. I''d really like it if somebody could help me. I''m an AE student.

Radiation intensity pattern of antennas, Q. Radiation intensity pattern of ...

Q. Radiation intensity pattern of Antennas? Antennas do not radiate power equally in all directions in space. The radiation intensity pattern describes the power intensity (whi

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