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

Frequency stability of quartz crystals, Q. Frequency stability of quartz cr...

Q. Frequency stability of quartz crystals ? The amount of frequency deviation from the ambient temperature frequency over the operating temperature range. This deviation is ass

Determine self inductance of coil, Determine self inductance of coil: ...

Determine self inductance of coil: A flux of 0.5 m Wb is generated by coil A of 600 turns wound on a ring with a current of 2 A in it. Determine (a) self inductance of coil A,

#title thyristor, what is finger voltage in terms of thyristor

what is finger voltage in terms of thyristor

Mainframes - introduction to microprocessors , Mainframes Computers lar...

Mainframes Computers larger than minicomputer more power  operating at very high speed  called  mainframes.  They  can processes 64  bit data.  Such computers are used  in defe

Current flow through the channel of a jfet after pinch off, Q. How does cur...

Q. How does current flow through the channel of a JFET after pinch off? It is seen that above the pinch off voltage at a constant value of VDS (saturation drain current, ID inc

What do you mean by frequency response, Q. What do you mean by Frequency re...

Q. What do you mean by Frequency response? Now let us examine the response of a circuit to a sinusoidal source, called an oscillator, whose frequency can be varied.Known as the

Analogue electric assignment, i have assignment about wien bridge oscillato...

i have assignment about wien bridge oscillator i need help to how to degsin the circuit using ltpsic

Nor gate - introduction to microprocessors , NOR Gate NOR means NOT OR ...

NOR Gate NOR means NOT OR . it complements the  output  of an OR  gate.  The symbol  of Nor  gate in fig. (a) shows that a Nor  gate  comprises  of an OR  gate followed  by a N

3-phase 3 wire meter with ct and md, 3-phase 3 wire meter with CT and MD ...

3-phase 3 wire meter with CT and MD It is exactly such as 3-phase 4 wire meter and works on the similar principle. It is also used in the similar way and under the similar cir

Determine the capacitor and inductor voltages, Experiment • Wire the circu...

Experiment • Wire the circuit shown in Figure. Connect the three oscilloscope channels as shown in Figure. • Select the sinusoidal waveform. Adjust the frequency of the input volt

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