Load curves

The curve showing the variation of load on the power station with respect to time

• The curve drawn between the variations of load on the power station with reference to time is known as load curve.
• There are three types, Daily load curve, Monthly load curve, Yearly load curve .

Types of Load Curve:

Daily load curve–Load variations during the whole day

Monthly load curve–Load curve obtained from the daily load curve

Yearly load curve-Load curve obtained from the monthly load curve

Daily load curve

Ø   The curve drawn between the variations of load with reference to various time period of day is known as daily load curve.

Monthly load curve

Ø   It is obtained from daily load curve.

Ø   Average value of the power at a month for a different time periods are calculated and plotted in the graph which is known as monthly load curve.

Yearly load curve

Ø   It is obtained from monthly load curve which is used to find annual load factor.

Base Load:

The unvarying load which occurs almost the whole day on the station

Peak Load:

The various peak demands so load of the station

Load duration curve:

When the elements of a load curve are arranged in the order of descending magnitudes.

The load duration curve gives the data in a more presentable form

Ø   The area under the load duration curve is equal to that of the corresponding load curve

Ø   The load duration curve can be extended to include any period of time