Terms Commonly Use in System Operation of Electrical Power Plant
Connected Load
- The sum of the continuous ratings of all the machines and equipments connected to the supply system is called as connected load.
- For example, if a household consumer has fixed 6 lamp points each of 40 watts, 4 fan points each of 60 watts and two power points each of 1000 watts, then the connected load of the consumer is 2480 watts. The sum of all such consumers connected load on the particular generating station or sub-station is called as connected load on that generating station or sub-station.
Firm Power
- The theoretical value of power which a hydro-electric power plant is supposed to produce throughout a year or at all times is termed as firm power. In case of plants having a reservoir, the firm power is that power which a hydro-electric plant can supply for 95% of the time. However, it is not necessary that firm power should be produced throughout the year and available even under emergency conditions.
Cold Reserve
- It is the reserve generating capacity which is available for service but is not in operation.
Hot Reserve
- It is the reserve generating capacity which is available in operation but is not in service.
Spinning Reserve
- It is that generating capacity which is connected to the bus and is ready to take load.