Question

请教大家一道电路题两台电器A和B并联工作,A是容性负载,视在功率3KVA,功率因数0.6.B是感性负载,视在功率1.5K

Answer 1

(1)

(2)

Qa = 3 * √（1 - 0.6^2）= 3 * 0.8 = 2.4 KVar

Qb = 1.5 * √（1 - 0.8^2 ）= 1.5 * 0.6 = 0.9 KVa

(3)

Pa = 3 * 0.6 = 1.8 KW

Pb = 1.5 * 0.8 = 1.2 KW

P = Pa + Pb = 3 KW

cosθ = P / S = P /√（P^2 + (Qa - Qb)^2) ≈ 3 /3.354 = 0.894