POWER SYSTEM STABILITY IMPROVEMENT USING STATCOM

Abstract

The static synchronous compensator (STATCOM) is being increasingly employed in modern power systems due to its capability to work as var generation and absorption systems. Besides the main task of voltage control, it is also applied to improve the transmission capability and power system stability. STATCOM is mainly used to perform voltage or reactive power regulation. In general, a compensator maintaining constant terminal voltage is not effective in damping of power oscillations. To damp power oscillations a supplementary control signal should be • added to the STATCOM Regulator. A multi objective comprehensive control system for the STATCOM combines the main control and supplementary control to hold constant bus voltage and improve power oscillation damping. This worli presents the detailed analysis of various 6-, 12-, 24-, and 48-pulse Voltage source Converters (VSC) and development of controller. A robust voltage controller is designed for a 48—pulse GTO based quasi harmonic neutralized voltage source converter based STATCOM. In addition to the main controller, a supplementary controller is designed to improve the small signal stability of a single machine infinite system. Simulations carried out in PSCAD and RTDS® show the efficacy of the controller design