The load curve is a graph that represents the variation of the electric load with time. It is drawn in a rectangular coordinate system, which represents the electrical load.
According to the nature of load, the load curve can be divided into two kinds of active load curve (the vertical coordinate indicates the active load value, the unit is kW) and the reactive power load curve (the longitudinal coordinate indicates the reactive load value, the unit is kvar).
According to the change of load, load curve can be divided into daily load curve and annual load curve. The daily load curve represents a day and night (24h) internal load change, and the annual load curve represents a year (87601h) in the case of load changes.
The load curve can be used to indicate the load change of a certain equipment, or the change of load of a unit.