. Non-Linear Stability (35 points) A round rotor generator is connected to a 60 Hz infinite bus. Problem data: Xs = 0.7 p. u. V = 1.00° p. u. Pm o = 1.2 Wp. u. |Eg| = 1.5 Vp. u. o = 0.594 rad H = 10.0 seconds At time t = 0, a three phase to ground fault occurs at point X, and the transmission line circuit breakers open to clear the fault. At time tB = 0.1 seconds braking resistor is switched in that instantaneously raises the generator output power to 0.6 per unit. a. (10 points) Find the values of the rotor angle and the rotor angular velcity at the instant the braking resistor is switched in, tB = 0.1 second. b. (10 points) The transmission line breakers reclose at tR = 0.3 seconds. At the same time, the braking resistor is switched out. Assume that the answers to part (a) are 0.8 rad and 1.8 rad/sec, respectively (they are not). Find the values of the rotor angle and the rotor angular velocity at the instant the breakers reclose, tR = 0.3 seconds. c. (15 points) If the value of from part (b) is 1.2 rad (it’s not), and = 0.8 rad, determine if the generator is stable or not stable for this transient.