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

Design an appropriate system, From a source with P in = 2.4 mW, we want to...

From a source with P in = 2.4 mW, we want to get P out = 60 mW at a distance l = 20 km from the source. α for the transmission line is given to be 2.3 dB/km. The available amplif

Explain loads - generation and absorption of reactive power, Explain Loads ...

Explain Loads - Generation and Absorption of Reactive Power A load at 0.95 power factor implies a reactive power demand of 0.33 kVAr per kW of power. When planning a network, i

Evaluate hysteresis loss, Q. A magnetic circuit is found to have an ac hyst...

Q. A magnetic circuit is found to have an ac hysteresis loss of 10 W when the peak current is Im = 2 A. Assuming the exponent of Bm to be 1.5, estimate Ph for Im = 0.5A and 8A.

Evaluate the form factor, Evaluate the form factor: For the saw tooth ...

Evaluate the form factor: For the saw tooth wave illustrated in Figure, find out the form factor. Figure: Saw Tooth Wave Solution Time period of given wave i

Calculate the induced voltage at full load, A 100-kW, 230-V shunt generator...

A 100-kW, 230-V shunt generator has R a = 0.05  and R f = 57.5 . If the generator operates at rated voltage, calculate the induced voltage at (a) full load, and (b) one-half fu

What is the maximum speedup, Question: (a) Explain the following metric...

Question: (a) Explain the following metrics: (i) Throughput (ii) Latency (iii) IPC (b) Of the three factors in the equation (EXCPU = Number of instructions × CPI × cy

Mathematics, The two sides of a triangle are 17 cm and 28 cm long, and the ...

The two sides of a triangle are 17 cm and 28 cm long, and the length of the median drawn to the third side is equal to 19.5 cm. Find the distance from an endpoint of this median to

Logically and the contents of memory, Logically AND the contents of memory ...

Logically AND the contents of memory Contents of memory  location,  whose address is specified by HL register pair are logically AND with the  contents  of the accumulator. The

Show that the output will be high, Considering the TTL NAND gate circuit of...

Considering the TTL NAND gate circuit of Figure, with one or more inputs low, show that the output will be high.

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