Bus Type - Known Parameter - Unknown Parameter Load Bus -P, Q - V, phase angle Generator Bus - P, V (magnitude) - Q, Voltage phase angle Slack Bus Voltage - magnitude and phase angle - P, Q
After closing switch, Capacitor is behave as short circuit element, So, I(to) = V/R = 10/5 2 At t = infinite time capacitor is behave as open circuit, I(t) = I(to)e^(-t/Ƭ) Ƭ = time constant of circuit Ƭ = R*C = 200 μF I(t) = 5*e^(-t/(500*10^(-6)) = 5*e^(-5000t) A
The ratio of full load current to short circuit current = 1/6 Xsc = j/(1/6) External reactance required = j*((1/6) - 0.06)) = j*0.106 pu Full load current = (40*1000)/(√3*15) = 1539.6 A Per unit reactance = j*0.106 = (I*Xr)/V j*0.15 = (1539.6*Xb)/((15/√3)*1000)) = 0.60 ohm