Free‐weighting matrices‐based robust wide‐area FACTS control design with considering signal time delay for stability enhancement of power systems

Abstract

This paper presents a free-weighting matrix (FWM) method based on linear control design approach for the wide-area robust damping (WARD) controller associated with flexible AC transmission system (FACTS) device to improve the dynamical performance of the large-scale power systems. First, the linearized reduced-order plant model is established, which efficiently considers the time delay of the remote feedback signals transmitted by wide-area measurement systems. Then, based on the robust control theory, the design of the FACTS-WARD controller is formulated as the standard control problem on delaydependent state-feedback robust control, which is described by a set of linear matrix inequality constraints. Furthermore, in order to obtain the optimal control parameters that can endure the maximum time delay, a FWM approach is proposed to solve the time-dependent problem of the time-delay system. Meanwhile, an iterative algorithm based on cone complementary linearization is presented to search out the optimal control parameters. Finally, the nonlinear simulations on the 2-area 4-machine and the 5-area 16-machine test systems are performed, to evaluate the control performance of the proposed robust wide-area time-delay control approach. 

Dissipative sampled‐data control of uncertain nonlinear systems with time‐varying delays

“…In recent years, the H ∞ sampled‐data control problem with system models expressed by dynamical systems has become a popular research topic and has gained extensive attentions . Also, to reduce the conservativeness, some of the researchers have used the free weighting matrix approach for the control design problems and it plays an important role in deriving delay‐dependent stabilization condition . Li et al obtained a state‐feedback and output‐feedback sampled‐data controllers to guarantee that the uncertain active suspension system is asymptotically stable and satisfy H ∞ disturbance attenuation level and suspension performance constraints.…”

Excitation and steam‐valving coordinated robust controller design for multi‐machine power systems based on the multi‐index nonlinear robust control approach

“…The transfer functions of PSS for generators G 3 where u PSS3 = ω 3 , u AVR4 = U t4 ; y AVR3 = E AVR3 , y AVR4 = E AVR4 . The physical limits of input signals are −0.…”

“…There are difficulties in dealing with control problems involving all controlled devices of power systems at the same time. Considering a specific device or some controllable devices in a local network of power system, control research includes the excitation control of generators [1], the coordinated control of excitation and the governor (steam valve or water gate) system for generators [2], and the coordinated control of the excitation system and flexible AC transmission equipment for power systems [3]. The above works, especially the coordinated control of excitation and governor system (CCEGS) for generators, can improve the steady-state and dynamic performance of power systems.…”

Applying sum‐of‐squares decomposition technique to power system robust control problem

“…Accordingly, there is a need for robust control in power systems, which takes care of the influence of uncertainties on the system in the process of system modeling and controller design. It has been one of the hot issues in power system control researches for several years [1][2][3][4]. Therefore, robust control approaches based on H ∞ control theory, passivity theory, adaptive control theory, etc., have been proposed to address the robust control problem of power systems [5][6][7][8].…”