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Sending and receiving power, 140∠10° and 132 kV

Short answer

Using ABCD parameters, receiving-end power is 183.51 MW and −17.25 MVAr; sending-end power is 192.11 MW and −5.43 MVAr.

Compute the sending end and receiving end power of a 3-phase line if A = 0.99∠0.1° and B = 18∠68° Ohm, if VS,L = 140∠10° kV and VR,L = 132∠0° kV.

Use the power-circle equations (taking D=AD = A). Line kV give three-phase MW/MVAr.

Data: ∣VS∣=140|V_S| = 140 kV, ∣VR∣=132|V_R| = 132 kV, δ=10∘\delta = 10^\circ, ∣A∣=0.99|A| = 0.99, α=0.1∘\alpha = 0.1^\circ, ∣B∣=18 Ω|B| = 18\ \Omega, β=68∘\beta = 68^\circ.

Constants

∣VS∣∣VR∣∣B∣=140×13218=1026.67∣A∣∣VR∣2∣B∣=0.99×132218=958.32∣A∣∣VS∣2∣B∣=0.99×140218=1078.0\begin{aligned} \frac{|V_S||V_R|}{|B|} &= \frac{140\times132}{18} = 1026.67 \\ \frac{|A||V_R|^2}{|B|} &= \frac{0.99\times132^2}{18} = 958.32 \\ \frac{|A||V_S|^2}{|B|} &= \frac{0.99\times140^2}{18} = 1078.0 \end{aligned}

Angles: β−δ=58∘\beta-\delta = 58^\circ, β−α=67.9∘\beta-\alpha = 67.9^\circ, β+δ=78∘\beta+\delta = 78^\circ.

Receiving-end power

PR=1026.67cos⁡58∘−958.32cos⁡67.9∘=544.05−360.54=183.51 MWQR=1026.67sin⁡58∘−958.32sin⁡67.9∘=870.66−887.91=−17.25 MVAr\begin{aligned} P_R &= 1026.67\cos58^\circ - 958.32\cos67.9^\circ = 544.05 - 360.54 = 183.51\ \text{MW} \\ Q_R &= 1026.67\sin58^\circ - 958.32\sin67.9^\circ = 870.66 - 887.91 = -17.25\ \text{MVAr} \end{aligned}

Sending-end power

PS=1078.0cos⁡67.9∘−1026.67cos⁡78∘=405.57−213.46=192.11 MWQS=1078.0sin⁡67.9∘−1026.67sin⁡78∘=998.80−1004.23=−5.43 MVAr\begin{aligned} P_S &= 1078.0\cos67.9^\circ - 1026.67\cos78^\circ = 405.57 - 213.46 = 192.11\ \text{MW} \\ Q_S &= 1078.0\sin67.9^\circ - 1026.67\sin78^\circ = 998.80 - 1004.23 = -5.43\ \text{MVAr} \end{aligned}

Line loss =192.11−183.51=8.60= 192.11 - 183.51 = 8.60 MW.

Answer: Receiving end: 183.51 MW − j17.25 MVAr; sending end: 192.11 MW − j5.43 MVAr.

✓ Answer checked by Claude Opus 5.5 (high effort)

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