Nonlinear control of power system multi-mode oscillations

This paper presents a method to design a new nonlinear power system stabiliser (NPSS), using the nonlinear feedback transformation technique and ITAE (integration of the production of time and absolute error) rule in the optimal control theory of linear systems, to deal with the control problem of multi-mode oscillations in large-scale power systems. The design of NPSS is carried out based on a multi-machine power system model. A decoupled nonlinear control strategy is obtained for individual machines and implemented using purely feedback of local variables. Performance of the proposed nonlinear stabiliser in the multimachine power system with multi-mode oscillations is digitally simulated The system responses controlled by the NPSS are compared with that obtained using the conventional PSS (CPSS), under different circumstances. The simulation results show that the NPSS can provide effective damping of the power system multi-mode oscillations and satisfactory control performance with good robustness. (C) 1997 Elsevier Science Ltd.