用戴维南定理解题,左图:
Uc = 10∠0° * (- j20)
= - j200∠0°
Uab = 10 * Is - 0.5 * Uc
= 100∠0° + j100∠0°
= 100√2 ∠45°
求 a、b 短路电流:
Isc = Is - 0.5 *Uc / 10
= 10∠0° + j10∠0°
= 10√2 ∠45°
Rab = Uab / Isc
= 10 Ω
I = Uab / (Rab + 10)
= 100√2 ∠45° / 20
= 5√2 ∠45°
求复功率:
U = 10 * I + Uc
= 50√2 ∠45° - j200∠0°
= 50 + j50 - j200
= 50 - j150
S' = U * Is* ;I* : I 的共轭复数,虚部为零就是自身。
= 500 - j1500
交流电最麻烦,你仔细核对。