Types of DC Generators

DC generators are broadly classified into two types, depending upon their field excitation. They are

• Seperately excited Generator
• Self excited Generator
• Shunt-wound Generator
• Series-wound Generator
• Compound-wound Generator
• Long shunt-wound Generators
• Short Shunt-wound Generator

Seperately excited Generator

In seperately excited dc generator, the field coils are excited or energized from an independent external source.

Applications of Seperately excited Generators

• Seperately excited generators are used in electropalting
• Seperately excited generators are used in electrorefining of material because seperate supply is required for field excitation.

Self excited Generator

In Self excited dc generator, the field coils are excited or energized by the current produced by the generator itself.

Shunt-wound generator

Shunt-wound generator is one type of self excited dc generator, here the field winding is connected in parallel to the armature. So, the full terminal voltage of the generator is applied across the field winding.

Applications of Shunt-wound Generators

• Shunt-wound generators are used in battery charging.
• Shunt-wound generators are used in ordinary lighting purposes.

Series-wound Generator

Series-wound generator is also one type of self excited dc generator, here the field winding is connected series with the armature. Since the field carries the full-load current, it consists of relatively few turns of thick wires, as show below. In series-wound generator, the resistance of the field coil is very low.

Applications of Series-wound Generators

• Series-wound generators are used as current generators for welding and arc lamp.
• Series-wound generators are used commonly as boosters on DC feeders.

Compound-wound Generator

Compound-wound generator is actually a combination of a few series-wound and a few shunt-wound generators. Compound-wound generator can either be long shunt compound-wound generator or short shunt compound-wound generator. If the series field helps or supports the shunt field, the generator is said to be cumulatively compounded. If the series field opposes or resist the shunt field, the generator is said to be differential compounded.

Applications of Compound-wound Generators

• Compound-wound generators are used in domestic lighting purposes and to transmit energy over long distances.
• Compound-wound generators are used in electric arc welding.