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

Fang Liu, Ryuichi Yokoyama, Yicheng Zhou, Min Wu

Research output: Contribution to journalArticle

7 Citations (Scopus)


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 delay-dependent 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.

Original languageEnglish
Pages (from-to)31-39
Number of pages9
JournalIEEJ Transactions on Electrical and Electronic Engineering
Issue number1
Publication statusPublished - 2012 Jan



  • Damping control
  • Flexible AC transmission systems (FACTS)
  • Free-weighting matrices (FWMs)
  • Linear matrix inequality (LMI)
  • Wide-area control
  • Wide-area measurement system (WAMS)

ASJC Scopus subject areas

  • Electrical and Electronic Engineering

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