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In this report some possible consequences of introducing demand response in the electric power grid are studied. Demand response is a part of the Smart Grid, which is a technology being developed to use our electric power grids more efficiently. Demand response programs aim to move people’s power usage over different times of the day, for example to distribute the power usage more evenly throughout the day or to permit a larger share of renewable, intermittent power sources in the system without making the delivery of electric power less stable.  A distribution system operator (DSO) can encourage customers to shift their power usage between different hours by various tariffs, for example by using time-differentiated or power dependent tariffs.   In this thesis, the change in power losses and possible environmental impact of introducing due to a power shift is studied. Power input curves from a DSO, Sala-Heby Energi AB, are studied and modified to simulate a power shift with an evened out electric power usage. The studies made show that in the best-case scenario, that is a electric power usage evened out to 100% each day, the power losses in the whole grid can be reduced with 2.6%. The environmental study shows that the result varies greatly with what method is chosen to do the calculations. The results are presented in kg CO2-equivalents (CO2e), and depending on method used they can either decrease or increase. The environmental study show that the environmental impact from the power usage is more dependent on the shift in power usage between hours than the decrease in electric power losses.

Recent in-flight instances of aircraft engine power loss involving hail ingestion have forced the manufacturers to demonstrate successful engine operation whilst ingesting hail. The main objective of this research project has been to obtain an understanding of the basic characteristics of hailstone impacts. A hail gun was designed to fire simulated hailstones at speeds up to 175 m/s. Three measurement techniques were used to determine the impact characteristics of the hailstones, i.e: patternator, high speed cine-photography, and still photography with short duration flashes. Using these techniques, the basic impact characteristics in terms of post-impact particle size, velocity and mass distribution were obtained for a variety of target configurations. The influence of seemingly important parameters on the impact characteristics were investigated, including approach angle and velocity, target curvature, and target rotation. Studies were further made into multiple impacts, and the effect of target curvature and rotation on the impact characteristics. Based on the experimental results, a set of empirical rules and a mathematical model describing hailstone break-up were defined.

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To measure losses in a transformer with today’s methods is either slow or insecure. There s a new method developed by Alstom that hasn't been actualize in to a test-system and that has been the assignment in this project. The idea is built on a switched system and a CLR- circuit in the resonant frequency. The test-system has a calculated power-loss that make the efficiency to be as high as 99,8% and in reality over 95%. But in the end it was discovered that the circuit was only able to deliver 70A when the thought was 200 A. More over was with the frequency of 200 kHz the signal was so distorted that all results over 100 kHz should be questioned. The goal was a efficiency of 99%. That was one of the basis in our calculation and dimensioning. When we order the components we foundbetter than we needed och the efficiency was improved. In the reality the efficiency is 95% and we think it's because the measurements-instruments accuracy and the distortion. In some measurements the efficiency went over 100% and that greatly improve that idea. Every part of the circuit was simulated piece bye piece and then together. That to increase the understanding of the system and to see that themodel works. The simulated efficiency was very low compared to calculated and in reality. The fact was gathered from literature, technical reports from Alstom and meetings with Per Ranstad et. al. / Om man vill mäta förluster på en transformator skerdetta antingen väldigt osäkert eller väldigt långsamt. Det finns en ny metod som Alstomtagit fram, som inte realiserats i ett bestående testsystem förrän nu, vilket har varit detta projekt. Det hela bygger på ett switchat system och en CLR krets i resonansfrekvens. Det resulterade testsystemet hade en beräknad verkningsgrad på 99,8 % och i verkligheten över 95%. Dock i slutskedet upptäcktes att kretsen endast orkade mata ut 70 A jämfört med det tänkta 200 A. Dessutom vid frekvensen 200 kHz blev signalen väldigt förvrängd av störningar och de resultat för frekvenser från 100 kHz och uppåt kan därför ifrågasättas. Vi satte ett mål på en verkningsgrad på 99% som vi grundade våra räkningar och dimensioneringar på. När materialet skulle beställas hittades bättre komponenter än vad vi satt upp och verkningsgraden förbättrades. Varför verklighetens verkningsgrad hamnar på 95% tror vi har med noggrannheten på mätinstrumenten att göra och störningssignalen. Vissa mätningar uppgick till över 100% verkningsgrad som gör att misstankarna för mätinstrumenten stiger. Alla kretsdelar simulerades bit för bit och ihop för att öka förståelsen för systemet samt se att lösningen funkar. Den simulerade verkningsgraden blev väldigt lågt jämfört med beräknat och verkligheten. Fakta vi använt kommer från flera litteraturer, tekniska rapporter från Alstom och möten med Per Ranstad m.fl.

The post-weld-shift (PWS) introduced in the butterfly laser packaging is investigated in this study. The elastic-plastic-thermal coupled finite element model is employed in the stress and deformation analyses. The temperature dependent material properties are used to calculate the residual stresses and the post-weld shift distributions during the packaging process. The finite element package ¡¥MARC¡¦ is used in this study. And the commercial optical software, i.e. ¡¥Zemax¡¦ is also employed in laser power coupling efficiency simulation. The variations of laser welding sequence, Nd-YAG pulse laser power, and initial ferrule¡¦s alignment position on PWS for butterfly laser packaging are studied and discussed in this work. The results indicated adjust the sequence and pulse laser power properly can improve the PWS in butterfly packing significantly. Besides, the PWS correction technique, i.e. the ¡¥Laser Harmering¡¦, is also illustrated in this study. The simulate results showed that proper arrange the welding processes may improve the coupling efficiency over 75¢M.

SSDs are now commonplace in all types of computing from consumer laptops to enterprise storage systems. However, most of those SSDs would not survive in environments with extreme temperatures or high shock and vibration such as found in embedded and military systems. The problems in this space are more than just mechanical; they involve all aspects of the design including electrical and even firmware. A combination of all three engineering disciplines is needed to provide a robust ruggedized SSD product.

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