A theoretical investigation of existing sensor techniques, bothcommercial sensors and scientific studies, has been performed inorder to find a cost efficient fluid sensor with the ability todetect small amounts of non-conducting fluids. From these studies,six different techniques could be distinguished. The techniques weretested and compared, both in theory and practically, against certaincriteria’s such as temperature and movement sensibility. Three of thetechniques have been proved to work and two of them were built,installed and tested on an industrial robot manufactured by ABBRobotics. The two most promising techniques distinguished were a photointerrupter and a Quartz Crystal Microbalance sensor. After tests itcould be concluded that both sensors fulfilled all preferences. However out of the two, the Quartz Crystal Microbalance sensorperformed best and could detect smaller amounts of fluid more quicklyand reliably than the photo interrupter. This work has resulted in a patent application.

The current demands for extremely high data rate wireless services and the spectrum scarcity at the sub-6 GHz bands are forcefully motivating the use of the millimeter-wave (mmWave) frequencies. The main characteristics of mmWave communications are severe attenuation, sparse-scattering environment, huge bandwidth, vulnerability to obstacles and antenna misalignment, massive beamforming, and possible noise-limited operation. These characteristics constitute a major difference with respect to legacy communication technologies, primarily designed for the sub-6 GHz bands, and are posing major theoretical design challenges that have not been sufficiently addressed so far. Motivated by these challenges, this doctoral thesis considers mmWave communications and investigates medium access control (MAC) layer design principles and performance analysis. Specifically, we focus on fundamental performance metrics, including coverage, fairness, robustness, throughput, and delay, which we address by three main research threads of increasing complexity. The first thread of the thesis analyzes the interference behavior in mmWave networks.We first propose a new index for assessing the accuracy of any interference model under any network scenario, which helps us develop a simple interference model of adequate accuracy. We then derive closed-form expressions for the throughput of mmWave ad hoc networks. The new analysis reveals that mmWave networks may exhibit a non-negligible transitional behavior from a noise-limited to an interference-limited behavior, depending on the system parameters such as density of transmitters, transmission power, and operating beamwidth. The second thread of this thesis builds on the previous one and addresses resource allocation in mmWave networks. For the short-term resource allocation, we establish a mathematical framework to investigate the impact of beam training (alignment) overhead on the network throughput. For the long-term resource allocation, we formulate a series of optimization problems that address relaying capability, frequent handovers, small multiuser interference, and load balancing. The third thread of this thesis extends the second one toward spectrum sharing in mmWave networks and characterizes the gains of beamforming and coordination in spectrum sharing via several optimization problems. We analyze these problems in the asymptotic regimes when the number of antennas becomes large and conclude that spectrum sharing with light on-demand coordination is feasible, especially at higher mmWave frequencies (for example, 73 GHz). The original analysis proposed in this thesis gives novel insights into many MAC layer issues such as resource allocation, interference management, random access, mobility management, and synchronization in future mmWave networks. The thesis also highlights that the design of mmWave networks poses open problems at the intersection of optimization and learning theories. Given the recent interest in the standardization of mmWave cellular networks and the highly sub-optimal nature of the existing standards for mmWave short-range networks, the results of this thesis may have the potential to substantially steer future standardizations. / <p>QC 20170523</p>

The aim of this thesis has been to investigate if it’s possible to build a system that can be used to automate the process of measuring environmental parameters, and to examine the performance of the system. This thesis describes the development of a mobile activity logger and presents the achieved performance of the system. It consists of three subsystems: The mobile unit, the base station and the NAS (Network Attached Storage). The mobile unit measures environmental parameters such as temperature and acceleration, and connects them to a measured GPS position and time. This data is sent to the base station using LoRa which transmits the data to the NAS using GSM where it is stored on an FTP-server. A client application has been developed for accessing the data and visualizing it on the screen. Amaximum range of 1.84 km during line of sight has been achieved between the mobile unit and the base station, with a theoretical battery life span of roughly 50 days. The system has a measured accuracy of 1-2 m in open areas.

<p>Vid tidpunkten för seminariet var följande delarbeten opublicerade: delarbete 4 under granskning.</p><p>At the time of the licentiate seminar the following papers were unpublished: paper 4 under review.</p>

Wireless control of lights is a 15HP project carried out at Uppsala University. Wireless control is used everywhere nowadays and the goal of this project is to create a prototype that can control the light intensity of an single phase lamp using wireless communication. Using this prototype, a solution of wireless control that can be applied for larger scale applications will be presented. By larger scale in this cases means more than the single lamp used for the prototype. The project uses WiFi and a server solution to communicate between the control unit and the light appliance. A small circuit was made to make it possible to control the grid voltage of 230 volt AC without damaging the microcontroller. The solution presented by this project works as intended. This solution can be modified to suit many different appliances, and not only control of lamps.

Detta examensarbete betraktar elkvalitetspåverkan som kan uppkomma till följd av att reläskydd och brytare utlokaliseras i ett kraftnät med radiell drift. Rapporten lyfter fram den potentiella problematiken som kan uppkomma på grund av ett förlängt frånkopplingsförhållande, förhållandet mellan spänningsdippens djup och dess korresponderande felbortkopplingstid, vid feltillstånd i nätet. Detta med utgångspunkt i befintliga föreskrifter samt ett tidigare utfört examensarbete som påvisade den samhällsekonomiska nyttan av en eventuell utlokalisering av reläskydd. Syftet med detta examensarbete är att fastställa om otillåtna spänningsdippar kan uppträda i kraftnätet till följd av utlokalisering av reläskydd. Det är även av intresse att undersöka om den samhällsekonomiska nyttan kvarstår då den tidigare ej betraktade dippkostnaden tages i beaktning. Detta genom att framställa en grundmetod för värdering av förväntade spänningsdippskostnader. Genom att observera spänningsdippars karaktär vid simuleringar i PSS/E för reella exempelnät framställdes illustreringar av spänningssänkningar samt korresponderande frånkopplingsförhållanden. Dessa frånkopplingsförhållanden används sedan i kombination med framtagna värderingsfaktorer för att beräkna en förväntad spänningsdippskostnad. Vilket leder till att den samhällsekonomiska nyttan kan fastställas genom att betrakta förändringen av avbrottsvärdering i relation till dippkostnaden. Med hänseende på otillåtna spänningsdippar förekommer det ingen risk för att sådana uppkommer i de undersökta exempelnäten. I arbetet påvisas även en total besparing för samtliga av de betraktade skyddsutlokaliseringsmetoderna. Dock förekommer det exempelnät där en mer ingående analys krävs för att en utlokalisering ska medföra besparingar för enskilda radialer. De besparingar som presenteras i rapporten innehåller en viss osäkerhet till följd av användandet av icke etablerade värderingsfaktorer. Detta medför att resultatet utgör en konceptvalidering och skall inte ses som en realistisk fallstudie av exempelnäten. Trots denna osäkerhet förespråkar författarna, utifrån examensarbetets resultat och avgränsningar, att utlokalisering av strömmätande reläskydd används som standardmetod vid utlokalisering. Även att nyttja möjligheten med att inkludera ett aktiverat snabbsteg bör användas då detta medför en förbättring av skyddets möjlighet att frånkoppla en majoritet av de mest kritiska spänningsdipparna momentant. / This bachelor’s thesis investigates the changes in electrical power quality that can arise from relocating switchgear and protection relays, from the power-feeding station, for a power grid with radial operation. The report highlights the potential problems with a prolonged faultclearance time in the power grid. The report uses existing regulations and a previously completed bachelor’s thesis, in which a substantial socioeconomic benefit was concluded, as a starting point for the study. The purpose of this bachelor’s thesis is to determine if unlawful voltage sags can appear in the power grid following a relocation of the switchgear and protection relay. There is also an interest in investigating if the earlier determined socioeconomic benefits remain if the previously unconsidered cost following a voltage sag is included. There is also included in the scope of the bachelor’s thesis to describe a basic method for evaluation of the expected cost of a voltage sag. By observing the nature of occurring voltage sags following simulations in PSS/E for proper power grids several illustrations over the magnitude and disconnection event were produced. The resulting disconnection event was then used in combination with estimated valuation factors to estimate the expected cost following a voltage sag. Which leads to that the socioeconomic benefits can be estimated by contemplating the change in cost following a forced outage in relation to the voltage sag cost. With regards to the occurrence of unlawful voltage sags in the examined power grids the bachelor’s thesis concludes that there is no risk for the appearance of such. The thesis also demonstrates that an overall socioeconomical benefit follows the use of any of the presented relay protection methods. Even though this benefit does not present itself in all the radials for the observed power grids following a relocation. In these cases, a deeper analysis is required to guarantee a positive outcome. The thesis contains an uncertainty with regards to the presented benefits following the use of non-established valuation factors. Following this the thesis should be viewed as a proof of concept and not as a in depth case study for the evaluated power grids. Despite these uncertainties the authors advocates, following the result of the thesis, for the use of relocated current measuring protection relays as a standard method when using relocated switchgear and protection relay. Furthermore, the authors also advocates for the activation of an instantaneous disconnection step, in the power-feeding station, in order to minimize the fault-clearance time of the most critical voltage sags.

Det här examensarbetet är utfört på uppdrag av Vattenfall Eldistribution AB och utfördes på deras kontor i Trollhättan. Syftet med projektet var initialt att påvisa att den idag planerade vägen till SAIDI-målet år 2025, troligen kommer att te sig annorlunda jämfört med de ursprungliga målen. Detta på grund av alla investeringar som görs i elnätet. Med dessa investeringar följer många driftorder, vilket ofta innebär planerade avbrott för kunderna. Det som undersöks är de eventuella störningar som kan kopplas till ett planerat avbrott. Det vill säga, om det har blivit ett följdfel på grund av ett planerat arbete, vilket orsakat ett kundavbrott som varade i minst tre minuter utöver den planerade avbrottstiden. Enligt Energimarknadsinspektionen delas begreppet elkvalitet upp i två olika parametrar; leveranssäkerhet och spänningskvalitet. Detta arbete fokuserar endast på leveranssäkerhet, närmare bestämt de långa avbrotten, vilket innebär avbrott som varar längre än tre minuter. För att elnätsbolag ska kunna jämföras finns det ett antal olika avbrottsindikatorer som exempelvis SAIDI och SAIFI. SAIDI är ett mätetal som fås fram genom kvoten mellan antalet kundavbrottsminuter och det totala kundantalet. Det resultat som framkommit går inte att rättvist jämföra med de historiska SAIDI-resultat som Vattenfall Eldistribution AB presenterar, då olika varianter av SAIDI används. Resultatet visar dock att en betydelsefull påverkan på SAIDI fås på grund av att det uppstår följdfel vid vissa kopplingar som görs i nätet, i samband med planerade arbeten. Dessa följdfel kan exempelvis bero på att en frånskiljare går sönder, fel i dokumentationen vilket leder till att fel apparat manövreras eller på grund av den mänskliga faktorn. / This thesis is made on behalf of Vattenfall Eldistribution AB and was conducted at their office in Trollhättan. The purpose of the project was initially to reveal that the way to the 2025‘s SAIDI-goal, probably will deviate from the original goal. This because of the many investments that are made in the power grid. These investments often lead to many switching schedules which often, for the customers, mean a planned interruption of the power supply. What is to be investigated is if there are any disturbances which are related to a planned interruption. Namely, if there was a secondary fault caused by the planned work, that caused a customer interruption that lasted longer than three minutes aside from the planned interruption time. According to Swedish Energy Markets Inspectorate, the concept of power quality divides into two different parameters; continuity of supply and voltage quality. This work will only focus on the continuity of supply, more particularly the interruptions which last more than three minutes. To enable comparison between electrical companies there are a few interruption indicators which for example are SAIDI and SAIFI. SAIDI is the quota of the total customer interruption time and the total customer quantity. The result that has been shown is not comparable to the historical SAIDI-results which Vattenfall Eldistribution AB presents, since different variations of SAIDI is being used. The result shows that a meaningful impact is to be received because of secondary faults occurring with some of the switching done in the grid, due to planned work. These faults could for example be rooted in a disconnector failing, flaws in the documentation that lead to manoeuvres of the wrong device, or simply because of the human factor.

Cognitive aids helps people with cognitive disorders to live a more ordinary life. Abiliais a company that develops and sells assistive technology to people with differentdisorders. One of their products, MEMOdayplanner 3, is a planning board that helpsusers to remember activities and structure their daily lives. The product consists of awhiteboard with integrated lights to help visualise the concept of time.The purpose of this thesis was to further develop the product and implement newfeatures and make it more user friendly. A prototype was to be built for testing andevaluation of said features. The work consisted of upgrading the electronic system toadd the new features and also make the unit cheaper and easier to manufacture.Different alternatives for a new user interface were investigated to find a solution thatwas easier to navigate and understand.The result was a working prototype that included an upgraded graphical user interfaceas well as several new features. The prototype provided more freedom to change andcustomize the product based on personal preference. Moreover, navigating the menusand changing settings were easier and more intuitive on the prototype compared tothe original product.

The electrification of the automotive industry is growing in popularity, considering the environmental impacts of the conventional diesel-powered automobile. However, from the electromagnetic compatibility (EMC) viewpoint, it is observed that the use of variable-frequency drives (VFD) and relatively high-power cables to propel electrical motors has led to a considerable rise in electromagnetic interference (EMI) within and outside the machine. EMI could come from the fast switching of the inverter, electromagnetic radiation from the high- power cables, common mode and differential mode currents as well as parasitic coupling of some of the components in the machine. The signals transmitted by near-by communication cables can be distorted as a result or, in the worst case, interference with the controller area network (CAN) bus of the machine.This thesis work aims to investigate different ways of mitigating EMI in battery-electric mine trucks used for underground mining. Having a three-phase system with power cables consisting of three conductors per phase per traction motor connecting the variable frequency drives (VFD) to the motors, the electromagnetic emission is significantly high because of the current level transmitted by the cables. This is in addition to the fast switching frequency of the inverter as the load/torque varies. Cable models are made using a finite element method (FEM) simulation tool, Ansys electronics desktop. The models are used to study how the cable shielding and material, arrangements and phase orientation can impact the radiated EMI within the machine. Experimental measurements are made in order to validate the models. Parasitic coupling between cables and components such as shield and protective earth conductors is considered to estimate the emitted magnetic fields. Results from one of the simulations show that a hybrid shield consisting of 50% Mu metal and 50% copper will give shield effectiveness up to 65% with reference to when an only copper shield is used. Mu-metal is the next most recommended shield because of the system low fundamental frequency. Steel shield gives as high as 20% better shielding than copper.Further simulations present the trefoil placement of the cable bundles, with the center bundle positioned upside-down compared to the two outer bundles, as a better option compared to when the cables within bundles are placed in a linear configuration, although the difference in the induces EMI is only approximately 5%.The major conditions for the above stated preferred arrangements include that bundles of cables within each bundle are tightly held together and the phase orientation is such that a cable is placed farthest away from the cable with the corresponding phase in the neighbouring bundle. Study on the effect of the connection of cable shield shows that common mode current is increased with the shield connected to ground through the body of the machine. This will give a considerable rise to both conducted and radiated EMI, but could help to reduce the risk of current flowing in uncontrolled parts of the machine.

Att ha en stabil bredning är viktigt för att uppnå noggranna dimensioner vid valsning av stångstål av hög kvalitet. Det här examensarbetet handlar om ett försök att konstruera ett enkelt, men ändå tillfredsställande, aktivt system för att reducera variationerna i bredning i Fundias mediumvalsverk i Boxholm. Att införa ett återkopplat reglersystem anses vara alltför komplext för att komma i fråga, så vi leds till att utnyttja framkoppling. Baserat på tillgänglig litteratur är det tydligt att temperaturen är den enskilt viktigaste faktorn att ta hänsyn till. Dock ger litteraturen inte någon metod som med tillräcklig precision förutsäger hur temperaturen kommer att påverka bredningen i vårt specifika fall. I stället får vi lita till en undersökning. Som tur är visar den att breddavvikelsen är approximativt proportionell mot temperaturen över hela det intressanta intervallet. Det gör det möjligt att basera systemet på en ”kompenseringsgrad”, som kan justeras av operatören. Ett sådant system konstruerades, installerades och testades, och det uppvisade mycket lovande resultat. / Having a stable spread is important in order to obtain accurate dimensions when rolling high-quality steel bars. This thesis describes an attempt to design a simple but adequate active system to reduce the spread variations at Fundia’s mid-section mill in Boxholm, Sweden. Introducing closed loop control is far too complex to be considered in this case, and thus we are forced to use an open loop approach. From the available literature, it is obvious that temperature is the single most important aspect to take into account. However, the literature does not provide the means to accurately enough determine how temperature variations will affect spread in our specific situation. Instead, we have to depend on an investigation. Fortunately, this investigation showed that the width disturbance is approximately proportional to the temperature throughout the interesting interval. This enables us to base the system on a “compensation factor”, set by the operator. Such a control system was then designed, installed, and tested, showing very promising results.