Analysis of Damping Torque and Synchronizing Torque Contributed by STATCOM Considering Two Different Damping Schemes

This paper studies the damping torque and synchronizing torque contributed by STATic Synchronous COMpensator (STATCOM), based on Pulse Width Modulation (PWM), in radial power system considering two different damping schemes: (1) the traditional damping scheme; and (2) a proposed damping scheme. Eigenvalue analysis is used to study the influence of the parameters of the Proportional and Integral (PI) of the dc voltage controller and ac voltage controller, real power, and reactive power as well as the damping controller gain of the STATCOM on the damping torque and synchronizing torque. Using a method developed in the literature, which depends on the time responses of the rotor speed, rotor angle and electrical torque, the damping torque and synchronizing torque coefficients are estimated and compared for different loading conditions and control parameters of STATCOM to confirm the results obtained from the eigenvalue analysis. Non-linear simulations of the STATCOM compensated radial power system using PSCAD are performed to validate the outcomes from the eigenvalue analysis and estimation of damping torque and synchronizing torque coefficients.