<p>The majority of all power cuts that affects individuals and communities are caused by earth faults on the power transmission lines at 10kV and 20kV level [1]. If these power cuts could be eliminated, less disturbances and interrupts would lead to large amounts of money savings.</p><p>Swedish Neutral has developed such a protection system. When an earth fault occurs power is injected into the neutral point of the transformer. The RCC (Residual Current Compensation) protection calculates a compensation current exactly 180 degrees out of phase to the fault current. Doing this, the voltage at the fault location becomes very close to zero, without affecting the power transmission.</p><p>The protection system can only compensate automatically for the fundamental frequency (50Hz), and manually for the 3^rd, 5^th, 7^th and 9^th harmonics. In most cases, when the harmonics are very small it is not necessary to compensate for them. There are though cases when compensation for the harmonics is necessary.</p><p>This thesis focuses on finding the best method to extract the content of a sampled signal regarding both simplicity and speed. Both amplitude and phase of each harmonic must be calculated. Is the proposed method suitable for the current computer system and how can it easily be implemented.</p><p>Because the fundamental frequency is known and the harmonics are all multiples of the fundamental frequency it makes the task less complex. It is not necessary to use the FFT algorithm. The DFT can be calculated using correlation. Both phase and amplitude can be calculated very precisely with few samples and not so many computer operations.</p>

Spectrally pure signals are an indispensable requirement when the Signal Generator (SG) is to be used as part of a test bed. However, even sophisticated equipment may not comply with the needs imposed by certain applications. This work approaches the problem by using Digital Pre-Distortion (DPD) based on a polynomial memory-less model obtained for the SG. Using the SG in arbitrary mode (ARB) an input signal is computer-generated and reproduced by the SG. Measurement accuracy is ensured using coherence sampling and grid matching to the Signal Analyzer (SA). Finally, careful time alignment is used to compare the transmitted and received three-tone signals to obtain the polynomials coefficients. Results show that the accuracy of the model and the effectiveness of pre-distortion may vary depending on the amplitude of the three-tone signal. However, using polynomials of 5th and 9th degrees up to 15dB reduction of the 3rd order Inter-Modulation products can be obtained, and spurious powers may be lowered down to 70dBc.

<p>This document provides a description about how the problem of the detection of thecenter of a defined geometry object was solved.This named object has been placed in an experimental environment surrounded bywater to be explored using microwaves under the water, to try to find a possibletumor. The receiver antenna is fixed in the tip of the tool of an ABB robot.Due to this working method, it was necessary to locate the center of this object tomake correctly the microwave scanning turning always around the actual center. Thiswork not only consist in give a hypothetic solution to the people who gave us theresponsibility of solve their problem, it is also to actually develop a system whichcarries out the function explained before.For the task of measuring the distance between the tip of the tool where themicrowave antenna is, ultrasonic sensors has been used, as a complement of acomplete system of communication between the sensor and finally the robot handler,using Matlab as the main controller of the whole system.One of these sensors will work out of water, measuring the zone of the object which isout of the water. In the other hand, as the researching side of the thesis, a completeultrasonic sensor will be developed to work under water, and the results obtained willbe shown as the conclusion of our investigation.The document provides a description about how the hardware and software necessaryto implement the system mentioned and some equipment more which were essentialto the final implementation was developed step by step.</p>

<p>Detta examensarbete tar upp frågan om kommunikationsproblem mellan de komponenter som ingår i ADDAX systemet, till största del de problem som uppstår mellan router och mätare. ADDAX systemet är uppbyggt på ett hierarkiskt vis med ADDAX server högst upp och mätaren längs ned. Systemet kommunicerar via PLC ”power line comunication”. Uppgiften har varit att kartlägga hur mätsystemet fungerar, vilka geografiska problemområden som finns med avseende på kommunikations problem, lokalisering av störkällor, åtgärdning av dessa störkällor och framtagande av ett flödesschema som skall kunna användas av montörerna vid felsökning i systemet. Arbetet inleddes med att ta fram underlag för vilka områden som påverkas av störningar i elnätskommunikationen. Detta gjordes med hjälp av programmet ”TC Meter Surv SA Edition 0.61” som arbetar mot ADDAX systemets databas för att se vilka mätare som är installerade och vilka som kommunicerar med systemet. Efter vissa problem togs två områden fram, ett på landsbygden och ett i centrala Grästorp. Vid mätning i dessa områden användes till en början två instrument, PL-monitor och HF+. HF+ visade sig vara överflödigt då samma information ges av PL-monnitor båda versioner visar på vilka störningsnivåer som finns i elnätet. HF+ är mer svårtolkat då användaren själv måste ta ställning till informationen som visas medan PL-monnitor enbart visar på den störning som stör ut kommunikationen. Då mätningarna genomförts och analyserats har det visat sig att programmet ej fungerat tillfredställande och att fel information om antal felaktiga mätare i de område som är beläget i centrala Grästorp, detta har resulterat i att en ny slutsats dragits där istället för en störning i LV nu problemet verkar ligga i MV. Kommunikations problemet på landsbygden kan troligtvis lösas med att installera filter hos de kunder vars mätare ej kommunicerar. Andra åtgärder som kan vara aktuella vid framtida kommunikationsproblem kan vara byta av kommunikations fas på mätaren, flytt av mätaren till matningsskåp, installation av repeterare eller att i samråd med kund få denna att stänga av störande utrustning vissa tider på dygnet. En slutsats som dragits av de erfarenheter som ackumulerats under projektets gång är att all mjukvara bör uppdateras och att master-routrar ersätts med en nyare version.</p> / <p>This report handles the issue of communication problems that appears between the components in the ADDAX system, mainly between the router and meter. The system is built around a hierarchy with the ADDAX server at the top and the meter at the bottom. The system uses the power grid as communication medium, this is called PLC “power line communication. The task has bin to se how the system works, witch geographical areas that have problems with communication, localization of source for the disturbing of the communication, attend to the disturbing and to make a flow chart that the electricians can use when they are conducting a measurement. A program called “TC Meter Surv SA Edition 0.61” was used for finding which areas that have problems with the communication. Two areas were chosen, one in the countryside and one in central Grästorp. The program firs showed that some meters where missing but when the measurements where don the program showed that all meters where missing. The reason for this problem is unknown. The problem in the central Grästorp area is not in the LV butt in the MV. The conclusion will be that al of the software must be updated and that the master routers could be replaced with a never versions before any new measurements are to be done. The power quality measurement instruments that has bin used are PL-monitor and HF+. On other conclusion that can bi don is that HF+ is superfluous because it chows the same information that PL-monitor dose but it’s harder to interpret. In the area on the countryside the solution to the communication problem can bi to install a filter. Other solutions to PLC problems can bi to switch the phase the meter uses for communication, move the meter farther from the customer, installing a repeater or in consultation with the customer get him or here to turn of the devise that disturb the communication under some ours in a 24-hour period.</p>

This thesis treats the development of an integrated optical sensor array. The sensors are slot-waveguide ring resonators, integrated with on-chip surface grating couplers and light splitters, for alignment tolerant, real-time, refractive index sensing, and label-free biosensing. The work includes: the design of components and system layouts, the development of fabrication methods, the fabrication of sensor chips, the characterization of the chips, and the development of physical system models for accurate extraction of resonance wavelengths in measured spectra. The main scientific achievements include: The evaluation of a novel type of nano-structured optical waveguide for biochemical sensing. The realization of an array of such slot-waveguide sensors, integrated with microfluidic sample handling, for multiplex assays. The first study of the thermal behavior of slot-waveguide sensors and the discovery of unique temperature compensation capabilities. From an application perspective, the use of alignment tolerant surface gratings to couple light into the optical chip enables quick replacement of cartridges in the read-out instrument. Furthermore, the fabrication sequence avoids polishing of individual chips, and thus ensures that the cost benefits of silicon batch micro-fabrication can be leveraged in mass production. The high sensitivity of the slot waveguide resonators, combined with on-chip referencing and physical modeling, yields low limits of detection. The obtained volume refractive index detection limit of 5 × 10−6 refractive index units (RIU), and the surface mass density detection limit of 0.9 pg/mm2, shows that performance comparable to that of commercial non-integrated surface plasmon resonance sensors, made from bulk optical components, canbe achieved in a compact cartridge. / Qc20100715 / SABIO

This document provides a description about how the problem of the detection of thecenter of a defined geometry object was solved.This named object has been placed in an experimental environment surrounded bywater to be explored using microwaves under the water, to try to find a possibletumor. The receiver antenna is fixed in the tip of the tool of an ABB robot.Due to this working method, it was necessary to locate the center of this object tomake correctly the microwave scanning turning always around the actual center. Thiswork not only consist in give a hypothetic solution to the people who gave us theresponsibility of solve their problem, it is also to actually develop a system whichcarries out the function explained before.For the task of measuring the distance between the tip of the tool where themicrowave antenna is, ultrasonic sensors has been used, as a complement of acomplete system of communication between the sensor and finally the robot handler,using Matlab as the main controller of the whole system.One of these sensors will work out of water, measuring the zone of the object which isout of the water. In the other hand, as the researching side of the thesis, a completeultrasonic sensor will be developed to work under water, and the results obtained willbe shown as the conclusion of our investigation.The document provides a description about how the hardware and software necessaryto implement the system mentioned and some equipment more which were essentialto the final implementation was developed step by step.

Detta examensarbete tar upp frågan om kommunikationsproblem mellan de komponenter som ingår i ADDAX systemet, till största del de problem som uppstår mellan router och mätare. ADDAX systemet är uppbyggt på ett hierarkiskt vis med ADDAX server högst upp och mätaren längs ned. Systemet kommunicerar via PLC ”power line comunication”. Uppgiften har varit att kartlägga hur mätsystemet fungerar, vilka geografiska problemområden som finns med avseende på kommunikations problem, lokalisering av störkällor, åtgärdning av dessa störkällor och framtagande av ett flödesschema som skall kunna användas av montörerna vid felsökning i systemet. Arbetet inleddes med att ta fram underlag för vilka områden som påverkas av störningar i elnätskommunikationen. Detta gjordes med hjälp av programmet ”TC Meter Surv SA Edition 0.61” som arbetar mot ADDAX systemets databas för att se vilka mätare som är installerade och vilka som kommunicerar med systemet. Efter vissa problem togs två områden fram, ett på landsbygden och ett i centrala Grästorp. Vid mätning i dessa områden användes till en början två instrument, PL-monitor och HF+. HF+ visade sig vara överflödigt då samma information ges av PL-monnitor båda versioner visar på vilka störningsnivåer som finns i elnätet. HF+ är mer svårtolkat då användaren själv måste ta ställning till informationen som visas medan PL-monnitor enbart visar på den störning som stör ut kommunikationen. Då mätningarna genomförts och analyserats har det visat sig att programmet ej fungerat tillfredställande och att fel information om antal felaktiga mätare i de område som är beläget i centrala Grästorp, detta har resulterat i att en ny slutsats dragits där istället för en störning i LV nu problemet verkar ligga i MV. Kommunikations problemet på landsbygden kan troligtvis lösas med att installera filter hos de kunder vars mätare ej kommunicerar. Andra åtgärder som kan vara aktuella vid framtida kommunikationsproblem kan vara byta av kommunikations fas på mätaren, flytt av mätaren till matningsskåp, installation av repeterare eller att i samråd med kund få denna att stänga av störande utrustning vissa tider på dygnet. En slutsats som dragits av de erfarenheter som ackumulerats under projektets gång är att all mjukvara bör uppdateras och att master-routrar ersätts med en nyare version. / This report handles the issue of communication problems that appears between the components in the ADDAX system, mainly between the router and meter. The system is built around a hierarchy with the ADDAX server at the top and the meter at the bottom. The system uses the power grid as communication medium, this is called PLC “power line communication. The task has bin to se how the system works, witch geographical areas that have problems with communication, localization of source for the disturbing of the communication, attend to the disturbing and to make a flow chart that the electricians can use when they are conducting a measurement. A program called “TC Meter Surv SA Edition 0.61” was used for finding which areas that have problems with the communication. Two areas were chosen, one in the countryside and one in central Grästorp. The program firs showed that some meters where missing but when the measurements where don the program showed that all meters where missing. The reason for this problem is unknown. The problem in the central Grästorp area is not in the LV butt in the MV. The conclusion will be that al of the software must be updated and that the master routers could be replaced with a never versions before any new measurements are to be done. The power quality measurement instruments that has bin used are PL-monitor and HF+. On other conclusion that can bi don is that HF+ is superfluous because it chows the same information that PL-monitor dose but it’s harder to interpret. In the area on the countryside the solution to the communication problem can bi to install a filter. Other solutions to PLC problems can bi to switch the phase the meter uses for communication, move the meter farther from the customer, installing a repeater or in consultation with the customer get him or here to turn of the devise that disturb the communication under some ours in a 24-hour period.

This review presents recent research advances in measuring native point defects in ZnO nanostructures, establishing how these defects affect nanoscale electronic properties, and developing new techniques to manipulate these defects to control nano- and micro- wire electronic properties. From spatially-resolved cathodoluminescence spectroscopy, we now know that electrically-active native point defects are present inside, as well as at the surfaces of, ZnO and other semiconductor nanostructures. These defects within nanowires and at their metal interfaces can dominate electrical contact properties, yet they are sensitive to manipulation by chemical interactions, energy beams, as well as applied electrical fields. Non-uniform defect distributions are common among semiconductors, and their effects are magnified in semiconductor nanostructures so that their electronic effects are significant. The ability to measure native point defects directly on a nanoscale and manipulate their spatial distributions by multiple techniques presents exciting possibilities for future ZnO nanoscale electronics.

För att kunna underlätta för sjukvården, både med avseende att belastning och för att underlätta för patienter med allergier mot t.ex. limmet som används för att fästa elektroder mot kroppen, arbetas det med att ta fram sensoriska plagg. Ett sensoriskt plagg kan användas för att kontrollera olika mätvärden i vardagen så som hjärtsignaler eller liknande och ska vara lätt för patienten att använda själv hemma. Eller som ett alternativ för någon som är allergisk mot det lim som vanligtvis används för att fästa sensorer mot kroppen. För att sensorerna i plagget ska kunna ge tydliga och användbara mätningar behöver de sitta stilla med ett jämt tryck på sensorerna mot kroppen. För att användaren av det sensoriska plagget ska vilja använda plagget och finna det bekvämt kan inte trycket mot kroppen vara för högt. Därför är det viktigt att ta reda på vilket tryck som uppfattas som bekvämt och vara funktionellt, men också är tillräckligt högt för att få en tydlig och användbar mätning. I denna rapport undersöks därför vilket tryck som uppfattas som gångbart ur användarsynpunkt. Undersökningen genomfördes med hjälp av elva deltagare som testat olika tryck och hur dessa tryck förändras under rörelse. Detta för att hitta vilket tryck deltagarna uppfattade som användbart och tillräckligt bekvämt för att använda i vardagen. Denna undersökning visa stora skillnader på vilket tryck som uppfattas som bekvämt och hur mycket trycket förändras under rörelse. Samt att statisk position inte påverkar signalerna från hjärtat anmärkningsvärt vid de undersökta trycken. / To relieve and ease a small part of the healthcare from work overload and help patients with allergies to glue used to attach the standard sensors, a sensor-equipped wearable garment could be used. The wearable garment could be used to monitor a patient´s values during the day and should be easy for the patient to use themselves at home and comfortable to use every day, or for a patient who is allergic to the glue usually used to attach the sensors. To make the sensors on the sensor-equipped garment work the sensors must sit with pressure against the body to get readable and useful measurement. The pressure from the sensors around the body can not be too tight if it gets too uncomfortable. Therefore it is important to find what pressure that is comfortable enough for the patient to use everyday but still get good enough readings from the measuring devise to be used to monitor the patient´s values. This study looks into what pressure that the participants perceive as comfortable to use on an everyday basis. In this study the pressure is measured on eleven different participants, the pressure was measured at different times and when the participants performed different movements too document the changes in the pressure at movement to find what pressure the participants perceive as comfortable enough for everyday use. This study shows that the pressure perceived as comfortable varies between participants and that the pressure change during movement. It also shows that static position do not affect the quality of the signals from the heart at the used pressures.

<p>In this project Fourier Transform Infrared Spectroscopy is used to investigate a new kind of photodiode that is based on nanowires. The photo current and I-V curves for different temperatures, different applied biases, in darkness and illumination condition have been studied. The experiment was conducted in the temperature range from 78 K (-195ºC) to 300 K (27ºC). These photo diodes are designed to work on NIR wavelengths. The results show some excellent properties, such as high break down voltage, and that is an important advantage for photo detectors, low and constant reverse saturation current (Is). The results show some defects, most of them come from fabrication. The design of the sample is also discussed.</p>