To study the improvement of transient stability of a power system using Flexible AC Transmission System (FACTS) controllers.
The student can compare four cases: Uncompensated, TCSC, SSSC and UPFC. A transmission-line fault is applied and cleared after a specified time. The resulting rotor-angle and electrical-power responses are displayed graphically.
All quantities are represented in per-unit unless otherwise stated. The model is intended for educational demonstration of transient stability concepts.
The four curves show the theoretical change in maximum power-transfer capability with FACTS compensation.
Rotor angle δ is plotted against time. The red vertical line indicates the fault-clearing instant and the orange line indicates the estimated critical angle.
Electrical power Pe is plotted against time. During the fault, the transfer capability decreases; after clearing, the FACTS controller restores a higher transfer capability.
Run the simulation to obtain the stability assessment.
| Case | Compensation | Xeq (pu) | Pmax (pu) | Maximum δ | Margin | Result |
|---|
The basic power-transfer relationship is approximately proportional to 1/Xeq. Therefore, reducing the effective transmission reactance increases the maximum power that can be transmitted.
TCSC provides series compensation by changing the effective series reactance.
SSSC uses a voltage-source converter to inject a controllable series voltage and provides additional damping.
UPFC combines series and shunt converter action and provides simultaneous control of voltage, impedance and power-flow angle.