Robust coordinated control of damping controllers for improving of dynamic stability in multi-machine environment

Abstract

In this paper, in order to improve the dynamic stability of multi-machine power system coordinated design of the unified power flow controller (UPFC) damping controller and power system stabiliser (PSS) is demonstrated. The coordinated design problem of PSS and UPFC damping controller over a wide range of loading conditions is converted to a constraint optimisation problem which is solved by a particle swarm optimisation (PSO) technique. The robustness of the coordinated stabilisers is warranted at wide range of operating conditions of power system. The effectiveness and robustness of the procedure are demonstrated through digital simulations on a four-machine power system embedding a UPFC and two PSSs. The performance of the coordinated stabilisers is presented through the non-linear simulation and some dynamic indices. The results of these studies illustrate that the proposed coordinated controllers have a distinguished capability in damping of inter-area oscillations and enhance greatly the dynamic stability of the power system.