It is defined as the highest demand of load on the power station for a given period of time.
The electrical load on the power plant varies from time to time. For a given period of time, the maximum of all the demands that occurs is termed as maximum demand.
Consider the daily load curve below:
The maximum demand at the power station is 5.5 MW at 19:00 hours.
The maximum demand is generally smaller than the connected load since all the consumers do not switch on their connected load to the system at once.
Importance of Maximum demand: The knowledge of maximum demand helps in determining the installed capacity of the power station and the power station should be capable of meeting the maximum demand.