Power station, whether or not in d.c. or a.c. stations, are usually found to possess many smaller generators running in parallel instead of giant single units capable of supply the utmost peak load. These smallest units will be run single or in numerous parallel mixtures to suit the particular load demand. Such apply is taken into account very fascinating for the subsequent reasons:
(i) Continuity of Service:
It is one amongst the foremost necessary needs of any electrical equipment. this could be not possible if the facility plant consisted solely of one unit, as a result of within the event of break- down of the prime mover or the generator itself, the whole station are shutdown. In recent years, the need of endless service has become therefore necessary particularly in factories etc. that it's currently familiar as an fiscal necessity.
Typically, the load on the electric power station swings amongst its peak value typically throughout the day and its minimum value throughout the late night hours. Since generators work most with efficiency once delivering full load, it's economical to use one little unit once the load is light. Then, because the load demand will increase, a bigger generator will be take the place of for the smaller one or another smaller unit will be connected to run in parallel with the one already operating.
(iii) Maintenance and Repair
It is thought of a decent apply to examine generators rigorously and sporadically to forestall any chance of failure or breakdown. This can be potential only the generator is at rest which implies that there should be different generators to require care of the load. Besides, once the generator will really breakdown, it will be repaired with additional care and not in a very rush, provided there are different generators available to maintain service.
(iv) Trappings to Plant
Additions to power stations are oftentimes created so as to deliver more and more larger load. Provision for upcoming extension is, in fact, created by the design engineers fight from the start. It becomes straightforward to feature different generators for operation because the load demand will increase.