Optimization and coordination of damping controls for improving system dynamic performance

This paper presents a global tuning procedure for FACTS Device Stabilizers (FDS) and Power System Stabilizers (PSS) in a multi-machine power system using a parameter-constrained nonlinear optimization algorithm implemented in a simulation program. This algorithm deals with such an optimization problem by solving a sequential quadratic programming using the dual algorithm. The main objective of this procedure is to simultaneously optimize pre-selected parameters of the FDSs and PSSs having fixed parameters in coping with the complex nonlinear nature of the power system. By minimizing a nonexplicit target function in which the oscillatory rotor modes of the generators involved and swing characteristics between areas are included, interactions among the FACTS controls under transient conditions in the multi-machine system are improved. A multi-machine power system equipped with a TCSC and an SVC as well as three PSSs is applied to demonstrate the efficiency and robustness of the tuning procedure presented. The results obtained from simulations validate the improvement in damping of overall power oscillations in the system in an optimal and globally coordinated manner The simulations also show that the stabilizers tuned are robust in providing adequate damping for a range of conditions in the system.