<p>This report aims to describe the work done in order to develop a solution for automation of failure detection and performance of rapid voltage surges. The automated system was developed with basis in the experimental circuit developed at NTNU/SINTEF. The experimental circuit relied on manually performing rapid voltage surges and detecting cable failure. Meaning that unknown variables may have been introduced due to the inequality of each grounding. The realized automation system consisted of two parts. The first part was a switch that was able to withstand the voltage applied and able to perform the rapid voltage surges. The second part was a program that controlled the switch and regularly monitored the condition of the cable object, indicating failure when electrical treeing had caused breakdown in the cable insulation. Two solutions for switches were examined. One switch utilized an arm moving between two electrodes for grounding the objects, using textile bakelite as insulation and support frame for the electrodes. The other switch utilized a sphere gap with air as insulation and an electric field strength close to the breakdown strengt of the air. Groundings in the sphere gap switch were performed using a striker to greatly enhance the electric field and cause a spark between the spheres, causing a transition from a highly insulating state to a highly conductive state. As the experimental circuit had a large current limiting resistance, the experimental circuit was sensitive to leakage currents as they set up a voltage over the resistance, instead of the cable objects. Leakage currents in the switches were examined and it was found that the arm switch had leakage current unacceptable for use in the experiment. Similarly, leakage currents in the sphere gap switch were examined and found to be acceptable for use in the experiment. The behaviour of cable objects that, due to electrical treeing had developed insulation failure was examined and measurement parameters for detecting cable failure were found. These parameters were implemented using LabView as a platform for creating a a control program and interface to the instruments connected to the switch. Having fully created the automated system, the system was used in testing cable objects and was found able to inflict and detect a cable failure due to electrical treeing. However, compared to previous results, a lower number of groundings were needed, which may indicate that the introduction of the sphere gap switch has altered the circuit in a manner such that new results will differ from former results.</p>

<p>As weather records are broken, and the topic of global warming and climate change, focus has been set on how this current development could be slowed or stopped. A change in paradigm must be conducted in order to address sustainable development. This paper has focused on how the field of industrial ecology and the tool of eco-industrial parks could be used to improve environmental performance of industrial systems. To evaluate the methods an industrial area at Moss has been further developed and new processes have been introduced. The system consists of an oxy-fuel CHP with carbon dioxide capture using the landfill gas as fuel, a urea plant, an ammonia plant to deliver ammonia to the urea plant and a cryogenic air separator plant providing nitrogen to the ammonia plant and pure oxygen to the CHP. Some carbon dioxide not used in the urea plant is used to increase the growth in a greenhouse. To evaluate the system, two simulation tools have been used. HYSYS has been used to simulate the processes involved and to arrange data for flow analysis. The heat exchanges had been assessed using Pro Pi 1, a tool specifically designed to create composite curves. Several simplifications have been made to easy the simulation. The CHP has an electric efficiency of 27 per cent and a total efficiency of 73,8 per cent. The electric exergy efficiency of the CHP is 28 per cent with a total system exergy efficiency of 67,7 per cent. The proposed system emits 35 per cent less carbon dioxide compared with stand alone processes. The system produce more heat then is needed to cover almost every process, and also the total demand in both the low- and high temperature district heating. The only process in need of external heating is the syngas reformer, which operates at such a high level that a stream of 46 kg/h of methane must be added. The output form the park is 8120 tonnes of urea annually, based on 8000 operating hours. The composite curves used to describe the heat exchange in the system proved to be a valuable tool when evaluating the need for utilities in the system. Both the material and energy flow analysis provided a good way to present energy and resource flows in the system. However, the exergy flow analysis proved to lack well developed tools to include irreversibility connected to the flows. Based on the guidelines presented from the Kalundborg EIP, the designed system could be called an eco-industrial park. However, economic analysis must be conducted to explore if there are economic incentives for the companies to develop such a park. Based on the experiences in this paper, further research should be made to develop better tools to calculate exergy losses based on HYSYS simulations. Also, an assessment of the economics connected to the system should be conducted.</p>

<p>The objective of this study was to develop an approach to integrate LCA of different fuels and energy conversion technologies into the energy planning tool eTransport. Course LCA's for relevant energy commodities, infrastructure and transport services was performed, and the results from these prepared for implementation in eTransport. In the choice of methodology for integration, a lot of aspects needs consideration. These are described throughout the report and emphasized in the choice of methodology. The methodology is illustrated by a case study on Trondheim municipality, followed by a description on how this would be done in eTransport. This project is a groundwork regarding implementation of LCA in eTransport, and will be followed up by further student work, testing the method in practice.</p>

<p>The increasing global demand for energy coupled with decreasing oil-supplies, and increasing risk of adverse climate change due to anthropogenic carbon emissions has created the need for combined economic and environmental assessment. This thesis attempt at devising such a framework based upon Life Cycle Assessment (LCA) and Life Cycle Costing (LCC). These methodologies represent two well established approaches for measuring environmental and economic performance of industrial projects and products. The LCA framework permits introduction of system expansion by interfacing with the greater economy by the hybrid-LCA. This approach also permits the assessment of life-cycle costs within the mathematical structure. The fundamental computations of LCA and LCC are introduced in this text in order to establish the combined assessment framework. This assessment method is applied to two National Renewable Energy Laboratory's studies on bio-ethanol production from lignocellulose. The studies are adapted to Norwegian economic conditions in order to assess the price and emissions of ethanol production from Norwegian wood mass. By combining these performance characteristics, a mitigation price of substituting gasoline with ethanol is established for various plant sizes as well as prices of gasoline.</p>

<p>In this work, a STAtic synchronous COMpensator (STATCOM) with energy storage system for wind power application has been treated. This device was proposed as a mean to improve voltage stability and power transmission by offering reactive as well as active power compensation. The work focuses on the converter topology of the STATCOM part and the control system. Further on, the energy storage system needed for this application was designed, including the choice of energy storage, its size and the interface/control system. The STATCOM, reactive part of the compensator was based on a voltage source converter (VSC), using a vector control. Its purpose was to maintain a stable grid voltage. For active compensation of wind power, a bank of super capacitors for energy storage system, SCESS, was used in this thesis. The super capacitor bank size was estimated, based upon the short term fluctuations in wind power. These fluctuations are results of contstructional factors of the turbines, variations and turbulence in the wind. The super capacitor bank was interfaced with the DC-bus of the STATCOM with a normal half-bridge buck-boost converter, to control the voltage level of the bank while maintaing a constant DC-bus voltage for good switching operation in the VSC. The control system for the active power compensation part was implented as a cascaded PI-control, compromising an inner current control loop, and an outer power control loop. The outermost loop included a dynamical power reference, based on the actual power transfer in the grid. This reference is supposed to assure that the controller is only compensating small fluctuations, while larger changes are left for other means, for instance controlled hydro power. The designed system was implemented in EMTDC/PSCAD. A small model, including one wind turbine, a weak grid and the STATCOM/SCESS was used in the simulations. With regards to the reactive- and active power compensation, the results were promising. However, the dynamical power reference could be of a better quality, as it does not take into account the losses in the STATCOM/SCESS, and thereby is inacurate regarding the amount power fed to/from the super capacitor bank. In addition, a small STATCOM model was realised in the laboratory. The results from the practical work showed the same general patterns as the simulations.</p>

<p>Artificial intelligence (AI) is a collective term for several computing techniques. They have in common that they use non-linear algorithms and that they are inspired from different processes in the nature, in particular how human beings make decisions. The use of AI for optimal operation of a stand-alone power plant has been investigated. This includes prediction, estimation, optimization and control. A presentation of some relevant AI techniques are given. A comparison with classical approaches such as for example PI control was made. The new techniques that were investigated proved to be very powerful and should be used more frequently than it is used today. AI techniques are especially promising for supervisorial control, but can also be used to control converters directly. A controller for a DC/DC boost converter was developed. It proved to be significantly better than a classical PI controller. Whether the computing time is shorter or faster than for classical approaches depends on the application. Compared to PI controllers the AI algorithms have a long computing time. Compared to classical wind power prediction techniques on the other hand AI techniques are very fast. A disadvantage with AI is the lack of rules for deciding the inner structure of the algorithms.</p>

<p>To create the ultimate wireless instrumentation unit for down-hole applications high temperature electronics with very high reliability is needed. It is possible to use ordinary bulk-CMOS devices at temperature up to 175 ⁰C, but the lifetime at these temperatures is to low for a down-hole instrumentation unit. An alternative is to use s Silicon on Insulator process under the fabrication of the semiconductors. The SOI process is a fabrication process where there is buried a oxide layer in the silicon wafer, and thus allowing higher breakdown voltage and/or lower current leakage. The low current leakage allows the semiconductors to be used at higher junction temperature. SOI devices that are commercial available off-the-shelf as a expected lifetime for at least 5 years at 225 ⁰C and thus much lower at junction temperatures below 200 ⁰C. The SOI technology can then be used together with hybrid circuits using ceramic substrate as a replacement for organic PCB and thick-film technology for the passive devices. A package like this gives a system with high reliability both toward high temperature operation and lifetime. The main limitation in the high temperature design is the availability off the larger capacitors; the limitation for high temperature stacked capacitors is 200 ⁰C. The converters designed are the standard step-up and step-down switch-mode power supplies. The converters are designed with current mode control; current mode control is used because of the advantage that comes with it. One off the advantages is the possibility to limit the inductor current; another advantage is the possibility to use constant current charging for the battery. When designing the SOI devices for high temperature operation it is difficult to achieve high enough breakdown voltage. With this in mind, the high temperature converter is designed with series coupled transistors to achieve high enough breakdown voltage for high voltage operation. The transistors have always some small perturbations in their specifications, this has to be considered when connecting transistors in series. This perturbations in for example turn-off speed makes an uneven voltage sharing; this is solved by connecting suitable capacitors in parallel with the switches to maintain an even voltage sharing.</p>

<p>This thesis offers a short overview of the most important stator mounted permanent magnet machines, with a closer look on the FSPM design. A FSPM machine have been built and tested as a generator, to get a better understanding of the machine concept. The focus of the work have been on the well documented 12/10 (Stator teeth/ Rotor teeth) design while the novel 12/14 pole design have also been tested, as a rotor change is the only difference between the two designs. The machine have been simulated in COMSOL, where inductances, back emf and cogging have been found and compared with the measured results.</p>

<p>To support the teaching in digital signal processing and control in power electronics a laboratory setup of a PV (photovoltaic) converter system is currently under development at NTNU. The equipment consists of a general reconfigurable power converter and a DSP (Digital Signal Processor) control card with system software for software development and testing. The finished system is intended for implementation in an African University to be used in teaching of PV systems. The power converter stage will be a dual stage consisting of a DC-DC converter and a DC-AC inverter connected to the grid through a transformer stage. For this particular master thesis the input stage comprising the PV panel and the DC-DC converter will be of main focus. A control design will be developed, comprising voltage mode control (with feedback from the input of the converter) and Maximum Power Point Tracking (MPPT). The DC link voltage level is set to be 48 V, while the input voltage will vary from 0 to 45 V. In the experiments the setup will consist of DC source simulating the PV-panel, a DC-DC converter and an electronic load representing the grid connection through an inverter and a transformer. The DC-DC converter was built and tested in a previous master project and can be configured as a buck, boost or buck-boost converter. For this thesis the boost topology was chosen, as this topology is the one most frequently used in PV systems. The control was implemented through C code programming. A regular voltage mode controller was developed and tuned through utilization of Ziegler-Nichols ultimate sensitivity method. At first a P-controller was implemented, but it was not able to cancel out the error between the reference voltage and the input voltage. This was expected, and an integral part was added to form a PI-controller. Now the closed loop control of the system turned out to be rather good for the whole range of the input voltage. The MPPT algorithm Perturb & Observe was chosen to track the maximum power point of operation. The MPPT was tested for both step changes in irradiance and temperature levels. When varying the irradiance level the current was the parameter most affected. Even though the MPP was tracked rather well there was uncertainty regarding the MPPT algorithm capability since the voltage was only exposed to minor changes. When the temperature was changed, the voltage was affected in higher degree. The MPPT was able to track the MPP rather well, and tracking in the wrong direction only happened right after a step change. In real life the temperature will normally not change in steps, so this test was said to be done under extreme conditions.</p>

<p>The goal of this study is to investigate the potential implementation of integrated dimethyl ether (DME) production from by-products of the pulp and paper industry in Fenno-Scandinavia (Finland, Norway and Sweden) and to quantify the consequences of several use scenarios in which fossil fuels were gradually substituted by DME. To that end, two analytical frameworks were jointly used, life cycle assessment (LCA) and environmentally-extended input-output analysis (EEIOA). The first framework was utilised to make an exhaustive inventory of the Chemrec process and its integration in the Finnish, Norwegian and Swedish contexts. The latter framework was employed in order to incorporate this production system into a multi-regional input-output model that has been created for the purpose of the study. For data availability reasons, the stressors that have been examined are anthropogenic carbon dioxide, methane and dinitrogen monoxide, widely regarded as the elements which are responsible for the most serious environmental impacts. Three different story lines (plus a baseline scenario) were taken into account: a resource assessment scenario, in which a total implementation is assumed; a policy-independent approach setting a constant increase in the use of biofuels and a policy-compliance approach, aiming at satisfying European directive goals. It results that 5.21 to 20.6 Mt of DME can be produced, while the range of greenhouse gases emissions that can be saved thanks to a black liquor-based DME production scheme goes from 46.7 (scenario 3) to 70.5 (scenario 2) Mt in 2050, that is, 8.15–12.8% out of the otherwise total emissions in Fenno-Scandinavia. This LCA/IO analysis emphasises that the amount of greenhouse gases emissions embodied in every kg of DME highly depends on each country's background economy and evolves considerably along the decade, unit-level analysis show drastic reductions (-15% to -57% between 2000 and 2050) in DME embodied emissions. A nationwide analysis highlights a very important potential from the Finnish pulp and paper industry. All in all, it shows that such a biofuel production scheme should be implemented in countries that have an remarkable environmental profile to obtain very significant environmental performances. Only a joint effort of all the key sectors (energy, transportation, households) can lead to climate change mitigation and energy security.</p>