Now showing 1 - 5 of 5
  • Publication
    On the Stability Analysis of Systems of Neutral Delay Differential Equations
    This paper focuses on the stability analysis of systems modeled as neutral delay differential equations (NDDEs). These systems include delays in both the state variables and their time derivatives. The proposed approach consists of a descriptor model transformation that constructs an equivalent set of delay differential algebraic equations (DDAEs) of the original NDDEs. We first rigorously prove the equivalency between the original set of NDDEs and the transformed set of DDAEs. Then, the effect on stability analysis is evaluated numerically through a delay-independent stability criterion and the Chebyshev discretization of the characteristic equations.
    Scopus© Citations 46  602
  • Publication
    Small-Signal Stability Analysis for Non-Index 1 Hessenberg Form Systems of Delay Differential-Algebraic Equations
    (Institute of Electrical and Electronics Engineers (IEEE), 2016-07-11) ;
    This paper focuses on the small-signal stability analysis of systems modelled as differential-algebraic equations and with inclusions of delays in both differential equations and algebraic constraints. The paper considers the general case for which the characteristic equation of the system is a series of infinite terms corresponding to an infinite number of delays. The expression of such a series and the conditions for its convergence are first derived analytically. Then, the effect on small-signal stability analysis is evaluated numerically through a Chebyshev discretization of the characteristic equations. Numerical appraisals focus on hybrid control systems recast into delay algebraic-differential equations as well as a benchmark dynamic power system model with inclusion of long transmission lines.
      340Scopus© Citations 48
  • Publication
    Small-signal stability analysis of neutral delay differential equations
    This paper focuses on the small-signal stability analysis of systems modeled as Neutral Delay Differential Equations (NDDEs). These systems include delays in both the state variables and their first time derivatives. The proposed approach consists in descriptor model transformation that constructs an equivalent set of Delay Differential Algebraic Equations (DDAEs) of the original NDDE. The resulting DDAE is a non-index-1 Hessenberg form, whose characteristic equation consists of a series of infinite terms corresponding to infinitely many delays. Then, the effect on small-signal stability analysis is evaluated numerically through a Chebyshev discretization of the characteristic equations. Numerical appraisals focus on a variety of physical systems, including a population-growth model, a partial element equivalent circuit and a neutral delayed neural network.
    Scopus© Citations 6  406
  • Publication
    Stability Analysis of Power Systems with Inclusion of Realistic-Modeling of WAMS Delays
    The paper studies the impact of realistic WideArea Measurement System (WAMS) time-varying delays on the dynamic behaviour of power systems. A detailed model of WAMS delays including pseudo-periodic, stochastic and constant components is presented. Then, the paper discusses numerical methods to evaluate the small-signal stability as well as the timedomain simulation of power systems with inclusion of such delays. The small-signal stability analysis is shown to be able to capture the dominant modes through the combination of a characteristic matrix approximation and a Newton correction technique. A case study based on the IEEE 14-bus system compares the accuracy of the small-signal stability analysis with Monte-Carlo time-domain simulations. Finally, the numerical efficiency of the proposed technique is tested through a real-world dynamic model of the all-island Irish system.
    Scopus© Citations 77  666
  • Publication
    Primal and Dual Generalized Eigenvalue Problems for Power Systems Small-Signal Stability Analysis
    (Institute of Electrical and Electronics Engineers (IEEE), 2017-03-07) ;
    The paper presents a comprehensive study of small-signal stability analysis of power systems based on matrix pencils and the generalized eigenvalue problem. Both primal and dual formulations of the generalized eigenvalue problem are considered and solved through a variety of state-of-the-art solvers. The paper also discusses the impact on the performance of the solvers of two formulations of the equations modelling the power systems, namely, the explicit and semi-implicit form of differential-algebraic equations. The case study illustrates the theoretical aspects and numerical features of these formulations and solvers through two real-world systems, namely, a 1,479-bus model of the all-island Irish system, and a 21,177-bus model of the ENTSO-E network.
      430Scopus© Citations 25