The three-phase alternator, Electrical Engineering

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



Posted Date: 8/23/2012 2:24:31 AM | Location : United States

Related Discussions:- The three-phase alternator, Assignment Help, Ask Question on The three-phase alternator, Get Answer, Expert's Help, The three-phase alternator Discussions

Write discussion on The three-phase alternator
Your posts are moderated
Related Questions
Compare CALL and PUSH instructions CALL PUSH When CALL is implemented the microprocessor automatically stores the 16-bit address of the instruction next to CALL on the sta

Register to Register  This  instruction  is used to copy data from the  source  register to the destitution register. The  previous contents on the  destination register wil

List the addressing modes supported by 8051. 1. Register addressing  2. Direct  addressing 3. Register indirect addressing 4. Immediate addressing 5.Register addres

which simulation software is better for this project, and how can i simulate it?

how do you get better at school

Q. Consider an RL series circuit excited by (a) v(t) = 20e -2t V, and (b) v(t) = 20 V. Determine the forced component of the voltage across the inductor for R = 2  and L = 2H.

principle and operation of a 3phace induction motor

The rotor of a wound-rotor induction motor is rewound with twice the number of its original turns,with a cross-sectional area of the conductor in each turn of one-half the original

This is basically a simple senior design project where the professors are giving us a limited budget and providing us with an Arduino Board. (We can use rasberry pi, beagle bone, e

Q. How can a JFET be used as a voltage controlled resistor. Explain from drain characteristics? The region to the left of the pinch off locus is referred to as the ohmic region