what is "reactive power"?

Reactive power refers to that in an AC circuit with reactance, the electric field or magnetic field absorbs energy from the power supply within a part of time in one cycle, and releases energy in the other part of time. The average power is zero throughout the cycle, but the energy exchanges continuously between the power supply and reactance elements (capacitors, inductors).Reactive power is mainly used to establish and maintain the magnetic field or electric field in electrical equipment. It does not do work externally, but has important significance for ensuring the voltage level of the power system, power quality and the normal operation of equipment.