Enhancing Transient Stability of the IEEE 9-Bus System Using SVC, STATCOM, Fast Exciters, and Line Reinforcement

Lyu Guanghua¹Gul Behroz Khan²Farah Akram²Syed Hadi Hussain Shah^1*Shoaib Shaikh³Wang Xiang¹Arsalan Muhammad Soomar^4*

• ¹PowerChina Huadong Engineering Corporation Limited, Hangzhou, Jiangsu Province, China
• ²Mohammad Ali Jinnah University, Karachi, Sindh, Pakistan
• ³Mehran University of Engineering and Technology, Jamshoro, Sindh, Pakistan
• ⁴Gdansk University of Technology, Gdansk, Poland

The electric power system (EPS) is frequently exposed to sudden disturbances such as faults, which can compromise rotor angle and frequency stability. As the energy landscape evolves, ensuring transient stability in conventional multimachine systems remains essential for grid reliability, particularly in the absence of renewable integration. This study investigates transient stability enhancement in the IEEE 9-bus system by evaluating and comparing four distinct strategies: Static Var Compensator (SVC), Static Synchronous Compensator (STATCOM), fast-acting exciters (EXST4B), and parallel transmission line reinforcement. The primary objectives are to compare the effectiveness of these techniques in mitigating rotor angle and frequency deviations under three-phase fault conditions; to identify critical fault locations through sensitivity analysis and determine optimal device placements; to assess the economic feasibility of SVC and STATCOM based on installation, maintenance, and operational costs; and to analyze fault-induced dynamic responses in a controlled conventional system, excluding renewable energy sources to isolate synchronous generator behavior. Simulation results using PowerWorld Simulator demonstrate that parallel transmission lines provide the most significant improvement in rotor angle stability, while fast exciters effectively reduce frequency settling time. SVC and STATCOM offer moderate performance but serve as valuable complementary tools, particularly in voltage-sensitive or weak networks. An economic comparison indicates that SVC is more cost-effective, offering a shorter payback period than STATCOM. These findings provide actionable insights for transmission system operators in selecting and deploying stability enhancement strategies in traditional power systems.