功率因數(shù)PF等于有功功率（千瓦）除以視在功率（千伏安），公式為：?PF = 有功功率（kW） ÷ 視在功率（kVA）。

打個(gè)比方，我們購(gòu)買一杯啤酒，以杯子大小來(lái)支付費(fèi)用。但是在杯子中有啤酒和啤酒沫，啤酒越多泡沫就越少，我們的花費(fèi)就更劃算。啤酒代表有功功率，是我們真正需要的有用的商品；泡沫代表無(wú)功功率，是沒(méi)用的商品，我們不能使用它，所以不想要太多。它們合在一起就是視在功率，是我們的實(shí)際功率。所以說(shuō)功率因數(shù)就是有用功率與實(shí)際功率的比值，或者說(shuō)是啤酒和我們所支付杯子大小的比值。您理解了嗎？

What is power factor?

Power factor (PF) is equal to the active power (kW) divided by the apparent power (kVA), expressed by the formula:
PF = Active Power (kW) ÷ Apparent Power (kVA).

For example, when we buy a beer, we pay the cost based on the size of the glass.

However, in the glass, there is both beer and foam. The more beer there is, the less foam there will be, making our spending more cost-effective.

The beer represents active power, which is the useful commodity we truly need; the foam represents reactive power, which is a useless commodity that we cannot utilize and therefore do not want too much of.

They together form the apparent power, which is the total power we actually handle. Therefore, the power factor is the ratio of useful power to the apparent power, or in other words, the ratio of beer to the size of the glass we pay for. Does this make sense?