Advantages of Power Plant Interconnections
Following are the major advantages of interconnecting various power stations and systems :
- Increased reliability of supply : If one of the power plant fails to supply the load due to fault etc. then the system can be fed from the other stations. Generation of power in a hydro-station is greatly affected by river flow, storage available, floods and draughts. Forced outages of steam power stations depend on efficient working of boilers, turbines and all the associated auxiliary plants. Forced outages as well as scheduled outages can be easily met in an interconnected system.
- Reduction in total installed capacity : The amount of reduction in total Installed capacity depends on the characteristics of the interconnected system and the desired degree of service reliability. The reserve capacity of the plant in any generating system is usually equal to the largest size of the plant in the system. When the power stations are not interconnected, the operation of power stations require one reserve unit of generator having capacity equal to largest size of the plant of each station separately. Similarly spinning reserve required in a power system reduced.
- Economic operation : It is essential to study the composite effect of all diversities that may exist in the power system. These diversities are due to occurrence of daily peaks in the load demand at different times of the day, some plant may need maintenance, due to its shut-down. Due to seasonal reason i.e. reduction in quantity of water available from rivers of catchment area of dam in summer or draughts etc. which will reduce the generating capacity of hydro-electric plants and steam plants capacity may be reduced due to shortage of water, less supply of fuel, coal etc. And sometimes the plant goes out of order (fails to work) due to some fault in generators, turbines, boilers etc. The composite effect of all these diversities can be evaluated by probability methods. Various methods of loading the generator units in the most economical way with interconnection should be studied. Savings derived from reduction in spinning reserve and economic loading of the generator units can be calculated. This will ultimately reduce the total capital cost and running cost to a minimum.