Open PowerWorld Simulator case Problem 11_21. This case models the Example 11.4 system with damping at the bus 1 generator, and with a line fault midway between buses 2 and 3. The fault is cleared by opening the line. Determine the critical clearing time (to the nearest 0.01 second) for this fault.

Example 11.4

The synchronous generator shown in Figure 11.4 is initially operating in the steadystate condition given in Example 11.3, when a temporary three-phase-to-ground bolted short circuit occurs on line 1-3 at bus 1, shown as point F in Figure 11.4. Three cycles later the fault extinguishes by itself. Due to a relay misoperation, all circuit breakers remain closed. Determine whether stability is or is not maintained and determine the maximum power angle. The inertia constant of the generating unit is 3.0 per unit-seconds on the system base. Assume \(p_{m}\) remains constant throughout the disturbance. Also assume \(\omega_{\text {p.u. }}=(t)=1.0\) in the swing equation.

Figure 11.4

Transcribed Image Text:

G XTA = 0.10 038 X = 0.30 B11 B12 F B13 X3 = 0.10 0.20 3 B21 X23 = 0.20 B22 2 XI Vous = 1.0