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

Find the speed of the motor, Q. A 10-kW, 230-V shunt generator, with an arm...

Q. A 10-kW, 230-V shunt generator, with an armature-circuit resistance of 0.1  and a field- circuit resistance of 230 , delivers full load at rated voltage and 1000 r/min. If the

Working of spectrum analyzer and its applications, Q.  Explain the working...

Q.  Explain the working of spectrum analyzer and its applications. OR Draw block diagram of spectrum analyzer and explain its operation write down its importance applica

Determine the maximum electric field in the depletion region, An abrupt sil...

An abrupt silicon (n i = 10 10 cm -3 ) p-n junction consists of a p-type region containing 10 16 cm -3 acceptors and an n-type region containing 5 x 10 16 cm -3 donors. a)

Describe the process design and application, Disinfection of water streams ...

Disinfection of water streams originating from potable water plants is key in protecting environmental health. Describe the process design and application, along with potential pro

Molecular chain, Molecular Chain (MIT, Princeton, Colorado) Consider a ...

Molecular Chain (MIT, Princeton, Colorado) Consider a one-dimensional chain consisting of N molecules which exist in two configurations, α, β, with corresponding energies  and

Defective metering and meter reading errors, Defective Metering and Meter R...

Defective Metering and Meter Reading Errors Defective Metering Tampered, slow running, stalled, damaged meters are a cause of huge losses to the utility. The electromecha

Clapp oscillator, having looked at the circuit, i first wanted to start my ...

having looked at the circuit, i first wanted to start my frequency from 0 and plot for 10000 to 20000. so in matlab i used f = 0:10000:20000; but the equation for frequency is f= 1

Armature winding, what is use of dummy coil in DC m/c????

what is use of dummy coil in DC m/c????

Explain ferrites and its uses in high frequency devices, Explain ferrites a...

Explain ferrites and its uses in high frequency devices. A group of magnetic alloys show the property of magnetisation that change, with percentage of various constituent atoms

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