Electric Circuits and Networks

9.8 PROBLEMS

1. A 400 V rms ∆-connected source shown in Fig. 9.8-1 has I₁ = 10∠−30° A rms, I₂ = 10∠−120° and I₃ = 10∠105° A rms. Find (i) the line currents delivered, (ii) the three-phase active power and reactive power delivered and (iii) a ∆-connected load that will result in this loading.

    

   

    

   Fig. 9.8-1

    

2. A star-connected source with zero source impedance delivers V_RY = 200∠−20° V rms, V_YB = 210∠−130° V rms. The R-phase phase voltage V_RN is 115∠0° V rms. Find the third line voltage and the remaining two phase voltages. Draw the phasor diagram ...