Power refers to the amount of work done by an object in unit time, that is, power is a physical quantity that describes the speed of work. The workload is fixed, and the shorter the time, the greater the power value.
Average power-also known as active power. The instantaneous power of alternating current is not a fixed value, and the average value of power in a period is called active power, which refers to the power consumed by the resistance part of the circuit, expressed by the letter P, and the unit is Watt.
The definition of "average power" in the reference book is the average value of instantaneous power absorbed or emitted by the circuits at both ends in a period. Average power is also called active power or active power for short. Let p represent power, p(t) represents instantaneous power, and t is the period. If the current and voltage at both ends of the circuit are sinusoidal waveforms with the same frequency, the average power absorbed by the circuit is P=UIcosφ, where U and I are the effective values of AC voltage and AC current respectively, and cosφ is the power factor.