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 working of digital-to-analog converters, Q. Explain working of Digi...

Q. Explain working of Digital-to-Analog Converters? Digital-to-Analog (D/A) Converters For the results of digital computations to be used in the analog world, it becomes n

Derive the solution of the characteristic equation, For a vehicle suspensio...

For a vehicle suspension, a basic two-degree-of-freedom "quarter-car" model would be slightly more complicated than the spring-mass-damper system I chose to study in Figure 1. The

For carry flag - return instructions , For Carry Flag  RC (Return of ...

For Carry Flag  RC (Return of Carry) and RNC ( Return on no Carry) Instruction RC returns from  the subroutine  to the calling  program if carry  flag is et (CY= 1). The

Determine the fraction of full load, The distribution transformer is supply...

The distribution transformer is supplying a load at 240 V and 0.8 power factor lagging. The open-circuit and short-circuit test data are given in Example. (a) Determine the frac

Determine the energy, Q. Consider a pair of coupled coils as shown in Figur...

Q. Consider a pair of coupled coils as shown in Figure of the text, with currents, voltages, and polarity dots as indicated. Show that the mutual inductance is L 12 = L 21 = M by

Requirement specification for the monitor and alarm system, Prepare a User ...

Prepare a User Requirement Specification for the monitor and alarm system. User Requirements Specification should be written in a clear and unambiguous manner to state: • The

Impurities in semiconductors, Impurities in Semiconductors Can be a...

Impurities in Semiconductors Can be added in accurately controlled amounts. Can modify the electronic and optical properties. Used to change conductivity over wide ra

What is the difference between photodiode and solar cell, A photodiode is m...

A photodiode is made to detect light quickly a solar cell is made to collect energy from light. They are both typically silicon diodes, but modified to meet their dissimilar requir

P-N junction, Explain how a p-n junction functions as a rectifier

Explain how a p-n junction functions as a rectifier

Obtain the laplace transform of the waveform, Q. Use MATLAB to obtain the L...

Q. Use MATLAB to obtain the Laplace transform of the waveform f(t) = [200t e -25t + 10 e -50t sin(25t)]u(t) which consists of a damped ramp and a damped sine. Also show 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