Search results for "Inert"
showing 10 items of 333 documents
Inertial response of isolated power networks with wind power plants
2019
The constant increase of power generation provided by renewable energy source (RES) power plants is causing a progressive reduction of the overall inertia of the power systems. Especially in the case of small, isolated power networks, the replacement of conventional generation plants with RES power plants can affect significantly the frequency response of the system. The critical low-inertia conditions can be improved by the introduction of specific additional controls to the RES power converters. These control schemes are known as “synthetic inertia” or “virtual inertia” controls. The paper analyzes the impact of a derivative-based inertial control on a small, isolated power system, with a…
System Stability of a Small Island's Network with Different Levels of Wind Power Penetration
2018
The reduction of the inertial response of the generation system has been one of the main obstacles to the penetration of high sharing of renewable energy sources in islanded systems. This issue can be solved thanks to innovative control that makes wind turbines able to provide the so-named synthetic inertia. The paper investigates some scenarios with different levels of wind power penetration in a small island whose grid is not supplied by the main grid, by the use of the software NEPLAN 360, simulating the wind power plants accordingly to the standard IEC 61400-27. The aim of the paper is to assess the maximum level of penetration in the island of wind generation, with traditional control …
An Analysis of the Intertial Response of Small Isolated Power Systems in Presence of Generation from Renewable Energy Sources
2018
Renewable Energy Sources are posing critical issues related to the mining of power systems stability, essentially due to a decrement of the inertial response during system's contingencies. As a consequence, to preserve the security and the reliability of the system, it is necessary to adopt new frequency adjustments mechanisms. This issue becomes particularly critical in isolated power systems, like those of small islands not supplied by the main grid, in the case of high shares of production from unpredictable renewabies such as photovoitaic and wind sources. In this framework, the present work deals with the analysis of the variation of the inertia time constant of a small island in vario…
Primary Frequency Control in the Power System of Continental Europe including the Dynamics of the HVDC Link France-Great Britain
2020
The paper presents a study of primary frequency control within the power system of Continental Europe (CE) including the dynamics of the high voltage direct current (HVDC) link between France and Great Britain (GB). The large-scale dynamic model of the CE system originally provided by ENTSO-E is extended with a more detailed representation of the whole HVDC interconnection. The dynamics of the GB synchronous area is also considered in the analysis, implementing a system equivalent suitable for primary frequency control studies. The opportunity of frequency containment reserve exchange between the two areas through the link is also investigated, considering supplementary frequency controls w…
Critical questions in diabetes management: What are the most compelling challenges and how can we handle them?
2022
Background: The prevalence of diabetes mellitus is growing worldwide, showing almost a 10-fold increase in the last five decades. Despite advances in the understanding of the disease mechanisms, preventive measures, and treatment options, morbidity and mortality remain high. Moreover, the burden of uncontrolled glycemia and associated complications have a significant impact on healthcare costs. To be ready for the future and emerging issues in the management of diabetes and related disorders, a holistic approach is essential for the prevention of the next generations. So many challenges in the management of diabetes exist globally, which differ according to the health infrastructure, and cu…
Sistēma muzikālās dzirdes attīstīšanai
2021
Kvalifikācijas darba ietvaros tā autors ir izveidojis un aprakstījis tīmekļa lietotni muzikālās dzirdes attīstīšanai balstoties uz muzikas izglītības nozarē izmantu metodi. Sistēma izstrādāta kā tīmekļa lietotne izmantojot PHP programmēšanas valodas satvaru Laravel, JavaScript programmēšanas valodas satvaru VueJS un InertiaJS, kas paredzēts abu satvaru apvienošanai monolītiskas sistēmas izveidei saglabājot abu satvaru labās iezīmes. Lietotne muzikālās dzirdes attīstīšanas funkcionalitāti veic intervālu atpazīšanas testu veidā attīstot dzirdes atmiņu un relatīvo dzirdi. Katrs lietotnes lietotājs var izveidot automātiski ģenerētu treniņu, pēc kura izpildes tiek saņemts treniņa pārskats, kas p…
Cautionnement. Article 2037, c. civ., Plan de redressement du débiteur principal imposant au créancier une remise de dette et la perte de son privilè…
1992
International audience; (Com. 16 avr. 1991, Venot c/ Banque de Neuflize, Schlumberger et Mallet).
Is experience a useful resource for business model innovation?
2016
ABSTRACTBusiness model innovation has been proposed as a powerful strategic tool, able to offer competitive advantage, create markets and even reshape industries. Despite these powerful effects, little research has been conducted into studying and improving business model generation methods, and even less study has gone into analysing how to define new business models that can exert a disruptive effect on markets and industries. Our work tries to fill this gap, analysing whether experience encourages or discourages the generation of disruptive business models. An empirical analysis was carried out using an experimental methodology. The results seem to contradict the currently dominant Resou…
Laparoscopic cholecystectomy in a patient with Steinert myotonic dystrophy. Case report.
2011
Myotonic dystrophy (MD) is a serious multi-systemic autosomal dominant disease. The estimated incidence is 1 in every 8000 births, with an estimated prevalence of between 2.1 and 14.3 cases per 100,000 inhabitants. Signs and symptoms vary from a severe form of congenital myopathy, present from birth and often fatal, to a classic form and a delayed form, which generally presents after the age of 50 and in which the only sign is a cataract and life expectancy is completely normal. We describe the clinical case of a 40-year-old woman with Steinert myotonic dystrophy who underwent laparoscopic cholecystectomy (under general anesthesia) for symptomatic gallbladder stones. The conduct of anesthes…
Fuzzy/Kalman Hierarchical Horizontal Motion Control of Underactuated ROVs.
2010
A new closed loop fuzzy motion control system including on-line Kalman's filter (KF) for the two dimensional motion of underactuated and underwater Remotely Operated Vehicle (ROV) is presented. Since the sway force is unactuated, new continuous and discrete time models are developed using a polar transformation. A new hierarchical control architecture is developed, where the high level fuzzy guidance controller generates the surge speed and the yaw rate needed to achieve the objective of planar motion, while the low level controller gives the thruster surge force and the yaw torque control signals. The Fuzzy controller ensures robustness with respect to uncertainties due to the marine envi…