Parallel Operation of DC Generators

Parallel operation of DC generators is required to meet the extra load demand. It is always difficult to meet the extra load demand by a single generator, or it is not possible to give supply when one generator is out of order. Some Reason for why to choose parallel operation of dc generator.

Reliability:

The generators that are sources of power are primarysafety items, and hence paralleled for reliability.

Efficiency:

The load is not uniform. It is mazimum during the ON-peak hours and minimum during OFF-peak hours. The generators must operate most efficiency during full-load condition. It is preferred to use a single generator during light load.

Continuity of service:

Un-interrupted power supply is most important thing to satisfy the customers. If one generator is used, it becomes impossible to deliver un-interrupted power supply during its maintenance hours or breakdown.

Requirement for Parallel Operation Of DC Generator

Paralleling FC generator is required mainly for the following two types of situations.

• Paralleling of shunt generators for the same or varying sizes.
• Paralleling of compound generators of the same and varying sizes.

Conditions for Parallel Operation Of DC Generator

• The terminal voltage must be the same.
• The polarities of the generator must be identical.
• The prime movers driving the armature of the generators must have similar and stable rotational characteristics.
• The change of voltage with the change of load must be the same character.