Comparison of effectiveness of auxiliary signals incorporated in STATCOM for improving transient performance of power system

Various auxiliary signal can be used for enhancing the damping performance of STATCOM. In this paper four auxiliary signals e.g. deviation in reactive power, deviation in active power, the combination of the two, and the deviation in bus voltage angle are incorporated in the STATCOM control system. The performance of various auxiliary signals has been evaluated by performing the eigenvalue analysis using a linearised system model. The time domain simulation study, using a nonlinear system model has been carried out under large disturbance conditions. It is established that combination of active and reactive power (CARP) when used in the STATCOM control system effectively damps out the power system oscillations.