5. Transient analysis with a classical generator model will be studied next for a three-phase bolted fault at bus 2. Assume the system is in its original state with bus 2 PD=720 MW QD=252 Mvar and PG3=520 MW before the new line was installed. Using the following parameters for the GENCLS model: G1: 400 MVA, H=1, D=1, Xd=0.24 G3: 800 MVA, H=12, D=1, Xd=0.24, determine the critical clearing angle, if any, that causes generator 1 to lose synchronism with generator 3. Consider G3 with its large inertia to be similar to an infinite bus. Load the DesignProject_GENCLS auxiliary file using PowerWorld's Add Ons: Transient Stability button near the top of the window. Note you must be in "Run Mode" to select Transient Stability. Use the "Load All Settings From" button in the lower lefthand corner to open the mem. Choose Load Auxiliary, and then select the proper AUX file. Modify the Time (Seconds) field in the Transient Contingency Elements record in the lower panel to control the time instant that the fault is cleared.
a. Use the formulas given in lecture to determine the critical clearing angle for generator 1, if any, using the internal power angle for generator 3 as a reference, similar to an infinite bus.
b. Use PowerWorld to determine the clearing angle that causes generator 1 to hit the highest angle it can without losing synchronism with generator 3. When you find the by first clicking on the small triangle in the lower righthand corner of the plot window, and then selecting the Export Chart option.
c. Compare the results from your formula-based calculation and the PowerWorld simulation.
6. Transient analysis with a two-axis generator model, IEEE Type 1 exciter, and TGOV1 governor. Note since controls are included with the detailed two-axis generator model, the artificial damping coefficient will be set to 0. I=0, bL9g=0, PL0=0, bXVZ0=0, PX0Z=0, bXIZ=0, PX0=qI=HVN00I, II0bL9=0, PL0=0, bXvZ0=P0Z=0, bZ=P0=qZI=HVXN008D. Determine the critical clearing time, within 0.001 s, that causes generator 1 to lose synchronism with generator 3, based on trial and error simulations with PowerWorld. Load the DesignProject_GENPWTwoAxis_IEEET1.TGOV1 auxiliary file to provide the required models to PowerWorld. When you find the critical clearing time, capture the generator power angle plot for the largest clearing time that is still stable, and the generator power angle plot for the clearing time that is unstable (0.001 s larger than the maximum clearing time that is still stable).