This report presents the main results from the knowledge-building project Vulnerability and security in a changing power system. The main stakeholders of this project are the energy authorities, system operators and network companies. The project has emphasized vulnerabilities in relation to...
Studies have shown that both char particle diameter and apparent density vary during char conversion at high temperatures. To account for such variations, power-law expressions have been used to correlate r p /r p,0 and ρ p /ρ p,0 with m p /m p,0. The parameters in these relations are constants...
The level-set method is a popular interface tracking method in two-phase flow simulations. An often-cited reason for using it is that the method naturally handles topological changes in the interface, e.g. merging drops, due to the implicit formulation. It is also said that the interface curvature...
The chemistry of lead and zinc in the bubbling fluidized bed combustion of recovered waste wood (RWW) was studied based on advanced thermodynamic equilibrium calculations. The condensation behavior of zinc and lead compounds in different parts of the boiler was evaluated, and the dependence of the...
The aim of directed Eulerian extension problems is to make a given directed, possibly arc-weighted, (multi-)graph Eulerian by adding a minimum-cost set of arcs. These problems have natural applications in scheduling and arc routing and are closely related to the Chinese Postman and Rural Postman...
I Norge kommer mer enn 90 % av distribuert produksjon fra småskala vannkraft. For distribusjonsnettselskap skaper integrering av slik produksjon en rekke utfordringer som krever navigering i et landskap bestående av mange aktører knyttet til både nett- og produksjonsutvikling; nettselskaper...
Failure frequencies for circuit breakers (CBs) (only single pressure ${rm SF}_{6}$), disconnectors and earthing switches, instrument transformers, and gas-insulated switchgear (GIS) have been determined through a comprehensive worldwide utility survey. For CBs and GIS, where comparable results from...
In a context of climate change, use of renewable energies should highly increase in the coming decades. Existing reservoirs and hydropower plants could be used to balance intermittent energy sources such as wind power and solar energy by pumping water from the downstream reservoirs and storing it in...
Thermodynamic modeling is used as a tool to predict the chemistry of ash-forming elements in biomass and waste combustion for corrosion- or deposition-related issues. One major limitation is the lack of comprehensive databases that contain the thermodynamic data of ash compounds and phases formed...
Den tjuende ”Faglærerkonferanse om enøk-undervisning” ble avholdt i Trondheim 31 mai og 1 juni 2012 med 15 deltagere. Konferansen arrangeres årlig i forbindelse med virksomheten til professoren i energiøkonomisering ved NTNU og den fungerer som et samarbeidsforum for faglærere i enøkrelaterte...
This paper presents the analysis of simulation-results of a Mini-Grid system consisting of two SEIGs 0.46 MVA and 0.23 MVA and voltage based generator controllers in SIMPOW®. The typical test-cases include simulation of SEIG, with lead-lag controller and PI controller in Mini-Grid system, when...
This paper addresses the needs for monitoring vulnerability in power systems related to extraordinary events. An analysis framework is described to identify threats, vulnerabilities, unwanted events and consequences. Vulnerability is an internal characteristic of the system comprising...
Denne kravspesifikasjonen er utarbeidet for å bidra til en felles forståelse om hvilke krav som er ønskelig ved fullskala utbygging av "Avanserte Måle- og Styringssystemer (AMS)" i Norge. Målsettingen er å etablere en kravspesifikasjon som nettselskap kan benytte som et utgangspunkt ved anskaffelse...