This report is a study in voltagelevel in connection with regeneration of brake energy from the tramtype M31 in Gothenburg.In the act of braking, the tram M31 uses electrical braking where the electrical motors generates energy and if possible send it back to the overheadline, where other trams in the nearby can use this regenerated energy for its own driving force. In cases where no other energyconsumers are located in the same section, there is a resistance witch task is to convert this energy into heat. The regulation of this resistance appears to cause an increase in the voltagelevel into far too high levels.Investigations of the trams regulationequipment and its construction have been done. Further have measurements on the overheadline been performed in order to map the voltagevariations during a longer period of time.The result have been showing that the voltagelevel during regeneration often is as high as 880V-920V, more extreme values have not been observed in a large scale. The values are especially high compared to the nominal voltagelevel.

This report is a study in voltagelevel in connection with regeneration of brake energy from the tramtype M31 in Gothenburg.In the act of braking, the tram M31 uses electrical braking where the electrical motors generates energy and if possible send it back to the overheadline, where other trams in the nearby can use this regenerated energy for its own driving force. In cases where no other energyconsumers are located in the same section, there is a resistance witch task is to convert this energy into heat. The regulation of this resistance appears to cause an increase in the voltagelevel into far too high levels.Investigations of the trams regulationequipment and its construction have been done. Further have measurements on the overheadline been performed in order to map the voltagevariations during a longer period of time.The result have been showing that the voltagelevel during regeneration often is as high as 880V-920V, more extreme values have not been observed in a large scale. The values are especially high compared to the nominal voltagelevel.

This report is a study in voltagelevel in connection with regeneration of brake energy from the tramtype M31 in Gothenburg.In the act of braking, the tram M31 uses electrical braking where the electrical motors generates energy and if possible send it back to the overheadline, where other trams in the nearby can use this regenerated energy for its own driving force. In cases where no other energyconsumers are located in the same section, there is a resistance witch task is to convert this energy into heat. The regulation of this resistance appears to cause an increase in the voltagelevel into far too high levels.Investigations of the trams regulationequipment and its construction have been done. Further have measurements on the overheadline been performed in order to map the voltagevariations during a longer period of time.The result have been showing that the voltagelevel during regeneration often is as high as 880V-920V, more extreme values have not been observed in a large scale. The values are especially high compared to the nominal voltagelevel.

This report is a study in voltagelevel in connection with regeneration of brake energy from the tramtype M31 in Gothenburg.In the act of braking, the tram M31 uses electrical braking where the electrical motors generates energy and if possible send it back to the overheadline, where other trams in the nearby can use this regenerated energy for its own driving force. In cases where no other energyconsumers are located in the same section, there is a resistance witch task is to convert this energy into heat. The regulation of this resistance appears to cause an increase in the voltagelevel into far too high levels.Investigations of the trams regulationequipment and its construction have been done. Further have measurements on the overheadline been performed in order to map the voltagevariations during a longer period of time.The result have been showing that the voltagelevel during regeneration often is as high as 880V-920V, more extreme values have not been observed in a large scale. The values are especially high compared to the nominal voltagelevel.

The purpose of this study is to examine young adults', 18-19 years old, attitudes towards corporal punishment and with the help of social constructionism, grid-group theory and relevant concepts analyze the results and compare it with previous research. The research questions introduce various factors such as gender, origin and personal experiences of corporal punishment that may affect the attitudes. In order to fulfill the purpose and answer the research questions, a quantitative research method has been selected. There was 118 participants in the survey. The study was conducted by means of surveys in high schools in Örebro. Social constructionism made us realize how the community, perceptions and expectations might influence attitudes. Grid-group theory gave us an insight into how different family structures may explain why attitudes toward corporal punishment of children differ between individuals.

Due to historically low prices for electricity in Sweden, many small-scale hydropowerplants were closed down. A small-scale power plant has more or less the samemaintenance costs as larger plants, but doesn?t generate as much income. Today?sincreasing price for electricity in combination with a desire for renewable energysources makes small-scale hydropower interesting again.

This report is an outcome of a master degree project at Linköpings University in co-operation with Micronic Laser Systems AB. The purpose with this master degree project was to investigate how to implement a receiver in a data transfer system. The system consists of several data channels, where every channel consists of three parts: driver, transmission lines and receiver. The driver send low amplitude differential signals via the transmission lines to the receiver that amplifies and converts it to a single-ended signal. The receiver has to be fast and be able to feed an output signal with high voltage swing.

Active work to increase the efficiency of energy use is taking place in Sweden and throughout all of Europe. Electricity is an important part in our society?s energy system which means that the electrical grid operators and associated therewith has a central role in this work. Monitoring and controlling the electrical grids are managed from the distribution system operator?s DC, dispatch center.The aim of this report is to examine how the operations in a typical DC on the Swedish electricity distribution network will look like in five to ten years.

During the period 2009-2013, investments in the Swedish national grid increase by a factor of ten compared to previous years. In order to fulfil their mission to manage the national grid in a safe, efficient and environmentally sound way, Svenska Kraftnät (Swedish National Grid) needs to take all these perspectives into account while planning new investments. To compare and relate perspectives of technology, economy and environment the same yard stick must be used. That yard stick is commonly money. A problem arises however as environmental issues are difficult to price.The purpose of this master?s degree project was to develop a tool for evaluation of environmental impact related to investments in the Swedish national grid.

Syftet med denna studie har varit att undersöka de svenska politiska partiernas åsikter gällande den förstärkning av personvalsinslaget som infördes år 1998 samt att fastslå hur dessa ställer sig gentemot en ytterligare reformering av valsystemet. Valreformer är historiskt ett politiskt område inom vilket det förekommit stora motsättningar enligt den traditionella ?höger vänsterskalan?. I studien analyseras huruvida dessa kvarstår efter den senaste reformen. För att ytterligare studera partiernas åsikter har dessa även analyserats i enlighet med Grid-Group teorins analysverktyg.

Historically transformers with system earth equipment have been modeled as open circuits in zero sequence. This approximation has been satisfying, but lately it has been discovered that equipment on one side of the transformer have responded to faults that occurred at the other side. Most of these problems took place when the majority of the system on the secondary side of the transformer contained cables. These findings have led to questioning whether or not the former model of the transformer in zero sequence is correct. This report investigates if it is necessary to represent the transformer in zero sequence in another way than it is usually done today.

In this thesis is studied the electrical load of Paradisskolan with respect to power quality and energy consumption. The school's owner Trollhättans Tomt AB is also interested to know if they can reduce their costs by changing to smaller meter fuses. A recurring ground fault that?s been recorded from powerpanel A1A has been investigated. The school's equipped with an electrical bonding system, harmonic filters for the third harmonic currents, TN-S system from feeding transformer and groundfault monitoring.

The aim of the project was to develop a method to investigate differences in adhesion of microorganisms to materials that contains lignocellulose. The method was tested on a gram-positive (Micrococcus lutea) and one gram-negative (E-coliJM109) bacteria.The study was begun by cultivation of the two microorganisms. The cultivation was done to calculate the generation times of the bacteria and to obtain growth curves. Cells from these cultivations were also frozen (-70ºC) and later used for inoculation.At STFI-Packforsk AB the total charge on the mass was measured and later a conductivity titration on the mass was executed as well, all to find out more about the different properties of the mass. Properties that in a later part of this study could possibly be linked to the adhesion of cells to the pulp.

Värnamo Elnät owns and operates a ripple control system which is used to control loadsespecially when the grid is heavily loaded and for control of street lighting. This report aims atclarifying technical and economic aspects of the ripple control system?s future. The system wasinstalled from 1975 and onwards and its use was greater in those days when the controllableloads where greater then today, the current controllable load level is about 3 MW. The reporthighlights three different aspects of the ripple control system?s future ? retain the currentsystem, reinvest in a newer system or discontinue the system.In the report the author also discusses relevant connections to Smart Grids and future meteringsystems and tariffs.

Abstract In high voltage substations there is an increasing demand for computerized equipment, and automation of operation and supervision. The future primary equipment will provide the possibility to collect more information and to provide better control for improved effectiveness. Since ABB has got a large customer target, each product must be custom made to fulfil the customers (often from different countries) demands. Later these products will be configured by engineers who may not be familiar with the tools used at ABB. This is a very expensive and time consuming.