Calculate the base quantities and draw the per unit equivalent Now, consider a 1LG fault with impedance ZF= j0.001 p.u. located at the load bus on phase A. The sequence networks for this configuration are illustrated in Fig. 2 below (next page). 2. Calculate the fault current IF given the equivalent circuit in 2.
Assignment Task
1. Problems – Symmetrical Components and Fault Studies
2. Given the following unbalanced currents IABC , determine the symmetrical components current vector I 012 .
3. Given the circuit from Fig. 1, and the quantities S 3p = 30MVA and V LL = 12 KV,
And using the following parameters:
| Generator | Line | Load |
| EG = 1.05∠0°p.u
S3p = 30MVA G VLL = 12 KV G XG= 0% (lossless) Balanced, wye-configured, and solidly grounded |
Xline = 3.6Ω |
ZL = (70 + j18) Ω Balanced, wye-configured, and solidly grounded |
Answer the following questions:
1. Calculate the base quantities and draw the per unit equivalent
Now, consider a 1LG fault with impedance ZF= j0.001 p.u. located at the load bus on phase A. The sequence networks for this configuration are illustrated in Fig. 2 below (next page).
2. Calculate the fault current IF given the equivalent circuit in 2.
3. Determine the phase currents I AG, I BG , and I CG oming out of the generator during the
4. How do the currents coming out of the generator compare to the currents going into the load?