无功功率

伏安无功（var）是交流电力系统中表示无功功率的单位。当交流电路中的电流和电压不同相时，存在无功功率。

Volt-ampere reactive (var) is a unit by which reactive power is expressed in an AC electric power system. Reactive power exists in an AC circuit when the current and voltage are not in phase.