Parallel Operation of Alternators
When the number of smaller units is connected in parallel instead of installing a large unit is called parallel operation of alternators. There are numbers of reasons, connecting alternator in parallel such as cost become less, maintenance and repair, efficiency and reliability of the power system. All the alternator of the system, work in parallel form a large capacity alternator. In this article, we will discuss about need for parallel operation of alternators
Need for parallel operation
In modern power systems alternators are operated in parallel to supply a common total load. Due to following reasons the alternators are connected in parallel.
- The demand of electrical power is huge, and it cannot be met by a single unit and it is difficult to build a large alternator, therefore to meet the demand of electrical power several alternators are connected in parallel.
- The parallel operation increases the reliability of the electric supply. If we use single large alternator in the event of fault on alternator or turbine whole the system is paralyzed. But with several alternators work in parallel maintain the continuity of supply rather than breakdown of one unit.
- Maintenance and repair of the alternator is more convenient if more number of small capacity alternators are installed at the power station. For repairing of one alternator there is no need to shut down the whole power plant.
- With increase the demand of electrical energy, we can install a alternator with existing plant.
- Transportation problems are faced with single large unit. But this problem can be eliminated by using small units.
- The load on power plant varies, usually having its peak value during the day and its minimum value during the night time.
Thus the number of units operating at a particular time can be varied depending upon the load at that time. If the alternators are connected in parallel the less efficient alternator can be shut down when the load requirement is less.