swing curve for a power system after a fault is cleared

code is simulating the swing curve for a power system after a fault is cleared

The code is simulating the swing curve for a power system after a fault is cleared. The swing curve shows the variation of the rotor angle of a synchronous generator with respect to time after a disturbance.

The simulation considers the effect of a fault and subsequent clearing of the fault after a specified time. The values of the fault clearing time tfl, the fault duration tf, the critical clearing time tc, and the time step ts are all specified in the code.

The pm variable represents the mechanical power input to the generator, while pm1, pm2, and pm3 are the perturbation amplitudes applied to pm during the simulation.

The swing curve is plotted using the plot function at the end of the code. The axis function sets the limits of the x and y-axis of the plot, while title adds a title to the plot.