Complete Guide to DC Generators

Hi, friends welcome to the new post. Here we will see the basics of DC Generator . It is an electric device that is used to transform mechanical power in electricity. Numerous types of DC generators are series dc generators, and shunt dc generator that performs the function according to their configuration.

The DC generator’s working operation relies on Faraday’s law of electromagnetic induction. DC generator performs different functions in industry and trains to offers electricity for load. In this post, we will see its different parameters with the details. So let’s get started.

What is a DC generator?

• The DC generator works on the magnetic principle for the conversion of mechanical energy into DC electrical power.
• EMF is induced in conductors when the magnetic flux configured with them varies. In the DC generator, there are two windings configured fields and the second one is armature.
• EMF is created with the use of armature winding is in rotation and coordinated through a commutator connected to a shaft.
• Armature is wounded on the rotor and field winding is wounded on the stator.

Construction of a DC Generator

Yoke:

• It is an external frame of DC machines where all inner structure is confined. It is created with the use of steel or cast iron. It provides strength to the assembly that also has field winding.

Poles 

• Poles are connected to the yoke through the use of welding. In these windings fields windings are applied and poles shoes connected there. The purpose of pole shoes is that support the field of winding and spread flux in the air gap uniformly.

Field winding:

• This winding is created with copper and they are put on poles and connected in series combination. They are wounded in such configuration when excited North and South Poles made

Bearings

• Bearings are used for the simple motion of different components of the DC machine. They reduce the friction between moving and static components. So it reduces the use of lubrication and works longer. Roll bearings and ball bearings are commonly used bearings for DC generators.

Commutator-

• Commutators are used for the conversion of AC voltage to DC voltage like rectifiers do.

Brushes

• The main purpose of carbon brushes make sure the electrical connection between the commutator and the external load circuit.

Shaft

• The shaft is a mechanical component that moves with the generation of torque. It comes with high breaking strength and is created with mild steel. The main purpose of this part of the generator is the transfer of mechanical energy.

 

How does a DC generator work?

• Faraday’s law of electromagnetic induction, says that current carrying conductor put in a magnetic field causes EMF.
• Based on Fleming’s right-hand rule, the direction of induced current varies when the direction of motion of the conductor varies.
• Suppose that the armature moving clockwise and the conductors are at the left. When the armature completed the half rotation, the direction of motion of the conductor reversed downward.
• So the direction of current in the armature varies. With split ring commutator connections of armature conductors reverse when curent changes. As result DC get on generator terminals

Types of DC generator

There are two main types of DC generators first one is separately excited and the second one self-excited.

Separately Excited

• Filed windings are energized from an external DC supply in this type of DC generator.

Self Excited

• In this generator, field windings get energized from the current produced in the generator. They are further classified in a series of wounds, shunt wounds, and compound wound generators

Applications of DC Generators

• For power and lighting separately excited DC generator is used.
• Series DC generator used for arc lamps and booster.
• DC generator used control voltage in feeders
• It is also used for providing power at homes, offices

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