Report: Types, Construction, Applications of AC and DC Generators

This report provides a detailed overview of AC and DC generators, focusing on their types, construction, working principles, and applications. It begins by explaining the construction and working of AC generators, highlighting the use of stators, rotors, and the principle of electromagnetic induction. It then delves into DC generators, describing their construction with yokes, poles, armature cores, brushes, and commutators, along with their operation based on Faraday's law of EMF induction. The report further discusses the applications and characteristics of both AC and DC generators, noting the wide range of applications for AC generators in automobiles, windmills, and hydroelectric dams, as well as their efficiency and voltage levels. For DC generators, the report emphasizes their use for constant loads and laboratory testing, highlighting their steady output voltage and suitability for charging batteries. The document concludes with a list of references.

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Table of Contents
Question 1: types and construction of generators................................................................................2
AC generator.....................................................................................................................................2
Construction..................................................................................................................................2
Working.........................................................................................................................................2
DC generator.....................................................................................................................................3
Construction..................................................................................................................................3
Working.........................................................................................................................................4
Question 2: application and characteristics...........................................................................................4
Applications and characteristics of ac generator...............................................................................4
Applications and characteristics of dc generator...............................................................................4
References.............................................................................................................................................6

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Question 1: types and construction of generators
There are mainly two kinds of generators used in the industries such as AC and DC
generators which are described below:
AC generator
Construction
The AC generator converts mechanical energy into the electric energy in the form of
alternative current. The construction of the AC generator involves the stator and rotor
where the stator is used to hold the windings of the armature and it is made by steel
alloys (Agbetuyi, et al., 2011). There are two kinds of rotors used in the AC generator
such as salient and cylindrical and the power supply is applied to the rotor winding with
the help of slip rings.
Figure: AC generator construction
(Source: Agbetuyi, et al., 2011)
Working
The AC generator works in the fundamental working principle of electromagnetic
induction. According to the low of electromagnetic induction when a conductor moves
in the magnetic field then an electromagnetic field produced across the conductor. If the
close path is delivered to the conductor then induced electromagnetic field can cause
the current to flow in the device.

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Figure: AC generator working
(Source: Agbetuyi, et al., 2011)
DC generator
Construction
Such kind of generator coverts the mechanical signals into the direct current and it can
be used as the DC motor. In the construction of the DC generator, four poles are
involved and divided into major two parts such as stator and rotor. The outer part of the
DC generator is defined as the yoke which is developed by cast steel (Wenxin, 2009).
Poles are joined to the yoke and coils and windings are developed with the help of
copper wire. There are several other parts involves in DC generators such as armature
core, brushes and commutator.
Figure: DC generator construction

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(Source: Wenxin, 2009)
Working
It works on the principle of EMF induction produced by Faraday. In which a conductor
is inserted in a magnetic field due to which an electromotive force in induced in the
conductor. If the conductor material is delivered with the closed part then the produced
current will circulate within the path.
Figure: DC generator
(Source: Wenxin, 2009)
Question 2: application and characteristics
Applications and characteristics of an ac generator
There are many applications of the AC generator such as automobiles, power generation
from windmills, and power generation from hydro-electric dams. The power rating of
the ac generator is up to 4000 KW from 4 to 12 poles and it provides between 92% and
97% efficiency in the industrial applications (Callegaro, and D'Elia, 2008). It is observed
that the value of voltage in the case of the AC generator is around 120 volts and above.
Applications and characteristics of dc generator
Mainly, it is suggested that the DC generator can be used for providing supply nearly
constant loads and testing purpose in the laboratories. In which the output voltage is
often steady and it does not change with the time and amplitude because the
commutator balances the value of voltage in the circuit (Milivojevic, et al., 2011). As
compared to the AC generator the value of voltage in DC generator is very low and it

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provides up to 500 watts power which is more enough to charge batteries. The overall
efficiency of the DC generator varies between 90% and 95% and it provides the
constant output voltage.

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References
Agbetuyi, A.F., Adewale, A.A., Ogunluyi, J.O. and Ogunleye, D.S., (2011) Design and
construction of an automatic transfer switch for a single phase power
generator. International Journal of Engineering Science, 3(1), pp. 4-8.
Callegaro, L. and D'Elia, V., (2008) A synchronized two-phase sinewave generator for AC
metrology system compensations. IEEE Transactions on Instrumentation and
Measurement, 49(2), pp.320-324.
Milivojevic, N., Krishnamurthy, M., Emadi, A. and Stamenkovic, I., (2011) Theory and
implementation of a simple digital control strategy for brushless DC generators. IEEE
Transactions on Power Electronics, 26(11), pp.3345-3356.
Wenxin, L.L.H.Y.H., (2009) Optimal Analysis of Reactive Capacity of Control Winding for
Dual Stator-Winding Induction Generator Operating With Variable Speed
[J]. Transactions of China Electrotechnical Society, 3(2), pp. 6-10.