Delay-dependent robust stabilization for steam valve opening of uncertain time-delay multi-machine power system with sector saturating actuator

In this paper, the time-dependent robust decentralized controller has been proposed for the steam valve opening of time-delay multi-machine power system with sector saturating actuator. Here, the nonlinear interconnected function is expressed by sinusoidal functions, and furthermore, is enlarged into quadratically bounded inequalities in the subsystem states via transformation of trigonometric functions. Two sufficient conditions of closed-loop multi-machine power system asymptomatic stability are derived based on Lyapunov stability theory and state transformation. Controller gain matrices are presented by solving linear matrix inequalities (LMIs). A two-machine infinite bus system is considered as an application example, and the simulation results demonstrate the effectiveness of the proposed method.

► Two sufficient time dependent conditions are derived.
► The nonlinear interconnection function is enlarged into quadratically bounded inequalities in the subsystem states.
► The LMI method has been used to compute the control gain matrices and define the bound of time delay.
► Two Theorems are compared from theoretical analysis and simulation result.
► The simulation results demonstrate the effectiveness of the proposed method.