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

Dc machines, importance of critical speed in dc generator

importance of critical speed in dc generator

Adi add immediate instruction , ADI Add Immediate  Instruction The  b...

ADI Add Immediate  Instruction The  bit  data specified in the instruction  is  directly  added with  contents of accumulator and result  of operation is stored  in the  accum

Mesh analysis procedure, Mesh analysis procedure : 1.  Assign a distinct...

Mesh analysis procedure : 1.  Assign a distinct current to every closed loop of the network. 2.  Apply KVL around every closed loop of the network. 3.  Solve the resulting

Asset information management system, Asset information management system: ...

Asset information management system: GIS has the potential to revolutionize the reform procedure in areas such as consumer indexing, asset and work management, distribution ne

Explain global positioning systems, Q. Explain Global Positioning Systems? ...

Q. Explain Global Positioning Systems? Modern communication systems abound in practice: cellular phones, computer networks, television satellites, and optical links for telepho

Signals and system, This is a project on music synthesis with sinusoids. Th...

This is a project on music synthesis with sinusoids. The project requires programming effort in Matlab, a software package which is installed in the computer labs in the School of

Microprocessor, distingish between maximum and minimum modes of operations ...

distingish between maximum and minimum modes of operations of 8086 with timing diagrames

Determine the synchronous speed in revolutions per minute, Q. Determine the...

Q. Determine the synchronous speed in revolutions per minute and the useful torque in newton- meters of a 200-hp, 60-Hz, six-pole synchronous motor operating at its rated full load

Boost converter - power supplies , Boost Converter The boost  convert...

Boost Converter The boost  converter has its  output  voltage always  greater than input  voltage like  a buck  converter boost  converter has two  modes.

Describe schmitt trigger, a) Describe Schmitt trigger with the help of tran...

a) Describe Schmitt trigger with the help of transfer characteristics. b) Also get the expression of hysteresis voltage VH and output waveform for sinusoidal input signal

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