Search results for "System stability"

showing 4 items of 14 documents

A Study of Power-Frequency Dynamics in Isolated Power Networks with 100% Converter-Interfaced Generation

2020

The operation of a system with 100% converter-interfaced generation poses several questions and challenges regarding various aspects of the dynamic characteristics of the system. The effects related to the power-frequency control are among the most relevant issues which need to be investigated. The paper takes into examination the case of an existing isolated power network of a geographical island assuming a completely converter-interfaced generation. The factors playing a fundamental role in the assessment of which sources should be designated to be grid-forming are identified with a small signal model formulation of a generic multiple oscillators system. Simulations and analysis performed…

Settore ING-IND/33 - Sistemi Elettrici Per L'Energiafrequency controlpower system stability100% penetrationConverter-interfaced generationvirtual synchronous machine (VSM)
researchProduct

Grid-Forming Converters in Weak Grids – The Case of a Mediterranean Island

2019

The existing power network of a Mediterranean island is used as test bed for the study of grid-forming converter dynamics in weak grid conditions. The control scheme adopted for the converter falls in the category of the so called virtual synchronous machines (VSM). Particular attention is committed to the interaction between the converter controls and the synchronous machines dynamics. Time delays typically associated to measurements and filters are considered in the study, and included in the system model with a specific mathematical approach. Time-domain simulations show the occurrence of oscillatory instability in the system, with VSM and synchronous machines swinging against each other…

Settore ING-IND/33 - Sistemi Elettrici Per L'Energiavirtual synchronous machinepower system stabilityweak gridvoltage source convertertime delayGrid-forming
researchProduct

Robust delay-dependent H∞ control of uncertain time-delay systems with mixed neutral, discrete, and distributed time-delays and Markovian switching p…

2011

Author's version of an article published in the journal: IEEE Transactions on Circuits and Systems I: Regular Papers. Also available from the publisher at: http://dx.doi.org/10.1109/tcsi.2011.2106090 The problem of robust mode-dependent delayed state feedback H ∞ control is investigated for a class of uncertain time-delay systems with Markovian switching parameters and mixed discrete, neutral, and distributed delays. Based on the LyapunovKrasovskii functional theory, new required sufficient conditions are established in terms of delay-dependent linear matrix inequalities for the stochastic stability and stabilization of the considered system using some free matrices. The desired control is …

delay systems H∞ control linear matrix inequalities Markov processes uncertain systems delay-dependent delayed state feedback distributed delays Lyapunov-Krasovskii functionals Markovian switching numerical example Stochastic stability and stabilization sufficient conditions uncertain time-delay system control system stability convex optimization delay control systems stabilization state feedback switching systems time delay uncertainty analysis discrete time control systemsVDP::Technology: 500::Mechanical engineering: 570VDP::Mathematics and natural science: 400::Mathematics: 410
researchProduct

Efficient finance regulator as supporter for financial stability of inhabitants

2020

Recent developments in banking sector in Latvia especially related with PNB Bank where bank accounts of many retired people were located leads to requirements for proficiency of Finance Regulator which has to be efficiently financed, stable and professional. In different countries Finance Regulators have different models of their financing. Aim of the study is to investigate different approaches for Finance Regulator financing and analyse expert views on possible development of Finance Regulator financing model in Latvia. Research methods applied: scientific publications and previous conducted research results analysis and expert survey for possible financing model changes in Latvia. In exp…

finance regulatorfinance system stabilityfinancial literacy:SOCIAL SCIENCES::Business and economics [Research Subject Categories]account location for retired people
researchProduct