Procedure for the transient stability analysis of single machine infinite bus system:

STEP 1: Single line diagram of power system for Pre-Fault condition is displayed. Enter the values of Bus Voltage (V, pu), Mechanical Power (Pm, pu), Transformer Line Reactance (Xt, pu), Transmission Line 1 Reactance (X1, pu), Transmission Line 2 Reactance (X2, pu), Inertia Constant (H), System Frequency (Hz), Time Step (s), Fault Occurrence Time (s) and Fault Clearing Time (s).

STEP 2: Click on 'Calculate'.


STEP 3: The single line diagram of power system for Fault condition will be displayed. The Power diagram for Pmechanical, Pre-fault, During Fault, Post- fault, Load angle vs Time (Swing Curve) and Frequency Curve will be displayed.

STEP 4: Refresh and change the Fault Clearing Time (s) to verify the Transient Stability behaviour of power system whether Stable or Unstable.

Note: Stable: The system is stable if the load angle oscillates with finite bounded amplitude.
Unstable: If the load angle starts increasing monotonically upon the inception of a disturbance, the system is Unstable.