Compared with input-to-state stability(ISS) in global version,the concept of local input-to-state stability(LISS) is more relevant and meaningful in practice.The key of assessing LISS properties lies in investigating three main ingredients,the local region of initial states,the local region of external inputs and the asymptotic gain.It is the objective of this paper to propose a numerical algorithm for estimating LISS properties on the theoretical foundation of quadratic form LISS-Lyapunov function.Given developments of linear matrix inequality(LMI) methods,this algorithm is effective and powerful.A typical power electronics based system with common DC bus is served as a demonstration for quantitative results.
WU ShengYu,MEI ShengWei & ZHANG XueMin State Key Laboratory of Power Systems,Department of Electrical Engineering,Tsinghua University,Beijing 100084,China
This paper proposes an assessment framework for branch parameter estimation of power systems,based on which the estimation accuracy can be improved and the estimation reliability can be ensured.The proposed framework comprises three parts:1) Parameter credibility assessment to evaluate the credibility of original parameters in the case that their true values are unknown;2) estimation accuracy assessment to provide quantitative information about the validity of the estimation;3) parameter dominance assessment to find out the key parameters for the estimation.This framework can be incorporated into the conventional parameter estimation process easily such that the accuracy and reliability of the estimation are improved.The implementation problems are addressed in details.Tests are carried out on the IEEE 14-bus system,IEEE 30-bus system,and IEEE 300-bus system to show the correctness and effectiveness of the proposed assessment framework.
