Improvement of Small Signal Performance of Multi Machine Power System Using SMIB Based PSS and STATCOM Designs

This paper discusses the improvements in small signal performance of a multi machine power system under the impact of Power System Stabilizer (PSS) and Static Compensator (STATCOM) devices. Parameters of both devices are optimized independently using MATLAB control system tools. PSS lead-lag network is designed using bode plot technique by analyzing Single Machine Infinite Bus (SMIB) based Heffron-Phillips model of network generators. STATCOM voltage regulator is optimized using a reduced STATCOM-Infinite bus model. The proposed designs are tested on a modified IEEE 14 bus system using MATLAB/SIMULINK. Simulations reveal that the system gains an appreciable damping ability against local modes of oscillation with PSS employed while STATCOMs increase this strength further. Results have validated the effectiveness of these SMIB based approximate modeling techniques in a multi machine environment where comprehensive system modeling is complex and often require information about whole power system which is sometimes hard to achieve.