If a three-phase fault occurs at the terminals of the machine as shown in Figure 10.5(a), the electrical
power output of the generator goes to zero and the accelerating power of the generator becomes
equal to Pm. Under the influence of this power, the rotor angle increases until the fault is removed
by the circuit breaker B. This is shown to occur at a rotor angle δc, as shown in Figure 10.5(b).
After the removal of the fault, the electrical power Pe is greater than Pm because the rotor angle δc
is greater than δ0. The rotor now begins to decelerate, and will begin to decrease after reaching a