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

Perfect gases avogadro''s hypothesis, Equal volumes of all gases contain th...

Equal volumes of all gases contain the samenumber of molecules when the volumes are measured at the same p and T. Therefore for a given volume at the same p and T, with the same

What do you mean by double word, Q. What do you mean by Double Word? A ...

Q. What do you mean by Double Word? A double word is precisely what its name implies, two words. Thus, a double word quantity is 32 bits. Logically, this double word can be div

Voltage regulator, Voltage regulator: A voltage regulator is an electr...

Voltage regulator: A voltage regulator is an electrical regulator intended to automatically keep a constant voltage level. A voltage regulator is an instance of a negative fee

Explain lda and daa instructions, Explain LDA, STA and DAA instructions ...

Explain LDA, STA and DAA instructions LDA copies the data byte into accumulator from the memory location particular by the 16-bit address. STA copies the data byte from the acc

Forth generation, Forth Generation VLSI  technology  of IC made it poss...

Forth Generation VLSI  technology  of IC made it possible  to design the  complete  circuit  of ALU  Arithmetic  logic unit and cu ( Control Unit ) within  single  chip  which

ERT, What are the applications for solar PV system? Explain one of the appl...

What are the applications for solar PV system? Explain one of the application with neat schematic diagram.

What is an opcode, What is an Opcode? The part of the instruction that ...

What is an Opcode? The part of the instruction that specifies the operation to be performed is known as the operation code or opcode

Find the average power absorbed by each element, Q. Let v(t) = Vmax cos ωt ...

Q. Let v(t) = Vmax cos ωt be applied to (a) a pure resistor, (b) a pure capacitor (with zero initial capacitor voltage, and (c) a pure inductor (with zero initial inductor current)

Determine flux in the central limb, Determine flux in the central limb: ...

Determine flux in the central limb: For the magnetic circuit shown in Figure the value of flux in the right limb is 0.48 m Wb and the number of turns wound on the central limb

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