For the NPCC system used in Problem 5.6, a fault was applied on Line 32-30 near Bus 32, and cleared by removing the line. The critical clearing time was computed using the constant-impedance model for all the loads. In this problem, repeat the critical clearing time computation, accurate to the nearest 0.01 sec, using constant power for all the active power loads and constant impedance for all the reactive power loads. Take the system as unstable if the simulation terminates because the network solution does not converge,

Problem 5.6

(NPCC system, Generator 11) Repeat Example 5.5, but the 3-phase short-circuit fault is applied on Line 32-30 close to Bus 32, which is cleared by tripping Line 32-30. Find the critical clearing time of Generator 11 using the PEBS method. Compare this result to the critical clearing time found in Problem 4.6.

Example 5.5