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

Control Charts, Control Charts The control chart is the fundamental to...

Control Charts The control chart is the fundamental tool of Statistical Quality Control (SQC). It denotes the general cause variation in which is built into a system therefore

Matlab code, Linear Equalizer and Decision Feedback Equalizer ...

Linear Equalizer and Decision Feedback Equalizer Simulation and Performance Comparison In this project , performance of decision feedback equalizer is analyzed,

Determine the voltage drop, A 15 volts source is applied to a series 150 mH...

A 15 volts source is applied to a series 150 mH inductor and 169 pF capacitor. The resistance of the inductor plus the connecting wires is 1,6 W. Determine the voltage drop and

Gis technology, GIS technology: GIS could be used to derive diverse in...

GIS technology: GIS could be used to derive diverse information for efficient technical and commercial management of a power distribution utility, e.g., capacity analysis, inv

The potential difference at the battery terminals, Ten 1.5V cells in series...

Ten 1.5V cells in series, each cells having an internal resistance of 0.3Ω, are connected series to a load of 25Ω. Determine : i.The current flowing the circuit

Explain light-emitting diode, Q. Explain Light-emitting diode? This is ...

Q. Explain Light-emitting diode? This is a reliable, rugged, and inexpensive semiconductor display device requiring about 10 mA of current flow for full illumination. An LED is

Circuit 1, draw a graph of V=IR for R=300ohms over the domain -3mA

draw a graph of V=IR for R=300ohms over the domain -3mA

Calculate reactive power to be delivered by the capacitor, A single-phase s...

A single-phase source delivers 100 kW to a load operating at 0.8 lagging power factor. In order to improve the system's efficiency, power factor improvement (correction) is achieve

Transfer characteristics of p-channel enhancement mosfet, Q. Explain the dr...

Q. Explain the drain and transfer characteristics of P-channel enhancement MOSFET. In p-channel enhancement MOSFET here is a n-type substrate and p doped regions under drain an

Calculate efficiency to load at unity power factor, Q. A 300-kVA transforme...

Q. A 300-kVA transformer has a core loss of 1.5 kW and a full-load copper loss of 4.5 kW. (a) Calculate its efficiency corresponding to 25, 50, 75, 100, and 125% loads at unity

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