变压器容量为100-630kVA，电机功率为几-几百kW，kVA为视在功为，kW有功功率，kVAR为无功功率。 有功功率与无功功率平方之和等于视在功率。 他们的关系是: 有功功率=视在功率*功率因素 即P=S*cosΦ。
Transformer capacity is 100-630kVA, motor power is several-hundreds KW, kVA is regarded as work in, kW active power, Kvar is reactive power. The sum of the square of active power and reactive power is equal to apparent apparent power. Their relationship is as follows: active power = apparent power * power factor P = S * cos φ.
如一台400kVA容量的变压器的长期负载最大不能超过400*0.83=330kW，（cosΦ取0.83）。
Such as a 400kVA capacity transformer long-term load can not exceed 400 * 0.83 = 330kw, (cos φ take 0.83) .
