An important process for grid companies in order to reduce Power losses in electricity distribution grids is to figure out where and how they appear. This report describes the factors that cause Power losses in low voltage distribution grids and methods for how they could be measured and analyzed. Measurement data for consumed and injected energy were collected for twelve low voltage distribution grids owned by Gävle Energi AB in order to analyze the size of the Power losses and how the measurement uncertainty affects the collected data. Then models of three of the grids were created in MATLAB in order to analyze the data and the Power losses were calculated to be compared to the collected data. Curve fitting were also used as a method in order to analyze the Power losses from collected data.The results show that the losses in the studied grids are low.

The technological legacy from the early electrification of the Swedish railroads has resulted in a power grid with a lower grid frequency than the national power grid from which it is fed. Energy transfer between these power grids with different frequencies requires substations, adapting the grid frequency for the rail road power grid. For this purpose, a feeding power grid has been built, stretching across the country from Boden in the north to Tälle/Häggvik in the south.Power transfer in the Swedish power grid results in voltage angle differences which increase with increasing loads and transfer distance. These voltage angle differences are transferred from the power feeding substations to the rail road power grid, will in some extent cause loss of energy due to unwanted power flows from north to south.To minimize the losses due to this phenomenon, a power management system called EFS 132 kV has been developed and implemented. The system minimizes the unwanted power flows and controls the desired power flow for a good distribution of loads between the power feeding substations.This thesis investigates the extent of the transmission losses avoided due to the EFS 132 kV that coordinates the idling angles to a common reference point.The results indicate that EFS 132 kV affects the power flow, especially between the northern substations through an improved load distribution.

Energy losses are an essential part of a power grid company?s costs. From anenvironmental and economic perspective, it is important to reduce these costs. Toknow where efforts should be deployed, it is important to have good knowledge ofwhere in the network losses are situated. When creating network tariffs, there is alsonecessary to have a correct distribution such that the network customers that use acertain part of the network, only pays for the network losses in this area.

This thesis was carried out at Atlas Copco Tools and Assembly Systems. The purpose hasbeen to develop a design tool to be used for development of new electric motors for AtlasCopcos electric nutrunners. The focus of the thesis has been to increase productivity bydecreasing the Power losses in an electric tool. The productivity is defined as themaximum number of tightenings a nutrunner can perform without becoming too hot.Before starting the development of this design tool an existing Matlab script, whichcalculates the losses in a slotless electric motor, has been studied and modified torepresent the real losses in a better way. The modification has been made by performingpractical studies of different losses and then adjusting existing parameters in the Matlabscript.Because design changes in one part of a mechatronic system can lead to a decrease inperformance of another part the choice of parameters that can be changed has been madeso that other parts of the system is affected as little as possible.A study of the existing tools efficiency during an entire tightening has been made toincrease the understanding of when and where the different losses appear and to comparethe modified Matlab script with the measured values.The design tool was formed so that it executes the Matlab script, that calculates thelosses, for a number of different design options and stores the alternative which producesthe least losses.

Storage of biomass is often associated with problems such as heat development, dry matter losses and reduction of fuel quality. The rise in temperature can potentially cause a risk of self-ignition in the fuel storage. Moreover, emissions from storage piles can cause health problems in the surrounding. The dry matter losses and reduction of fuel quality can have economical effects. The aim of this thesis project is to develop guidelines on how to store large amount of biomass at Vattenfalls heat and power plants in an optimal way.

One step towards a more sustainable energy system is to create a more flexible electrical grid, where increased demand response among electricity consumers can play an important role. A distribution grid owner can encourage their customers to use electricity more evenly distributed during the day by introducing different types of grid fees such as time-differentiated power tariffs. In this master thesis, the theoretical economic impact of a flattened load profile for a distribution grid owner is investigated. Different factors that impact the distribution grid owner?s economy are identified and two are chosen to be quantified; losses in the grid and the fee to the feeding grid.

A large number of rivers in northern Sweden have hydropower developments that cause negative effects on both up- and downstream migrations of anadromous species like Atlantic salmon. So far, most attention has focused on the hindrances of adult fish during their upstream spawning migration. However, since turbines in power stations cause losses on downstream passing fish, the focus on negative effects on smolts has increased. The aim of this study was to compare three different causes of losses of salmon smolts passing downstream through a power station area in the flow-controlled River Åbyälven in northern Sweden.A total of 61 wild salmon smolts were caught and radio-tagged in the River Åbyälven during their downstream migration in June 2009. The salmon smolts were released at three locations, 1.1 km upstream from the power station, in the turbine intake and in the upper part of a fishway, acting both for up- and downstream fish passage.

Transmission of reactive power is well known to cause active Power losses. Thus, newcomponents who can help minimizing these expensive reactive power flows are ofgreat interest to the power distribution companies. ABB Corporate Research hasdeveloped the first electronic power breaker. One possible application for thisbreaker is transient-free switching of capacitor banks. This could prove a usefuldistribution voltage complement to the switch-sync technique, mainly applied to transmissionvoltage level.

Wind power is expanding rapidly in Sweden. Increasing amounts of wind power sets higher requirements on balancing power and grid expansions and would affect the whole Swedish electricity system. The aim of this report is to examine the factors affecting the wind power expansion in Sweden. How many wind power plants projects will obtain building permissions and what costs and revenues can be expected? How much balancing power will be required and does a changing geographical distribution of the wind power plants reduce the need of balancing power?A survey of the county board?s official applications has been made and out of all the applications, corresponding to 80 TWh produced per year, about half of the applications are expected to obtain a permit with a major portion of them located in the north of Sweden.Especially older wind power plants, deriving revenue from Nord pool, find themselves today in a complicated financial situation.

Storage of biomass is associated with problems like heat development, biomasslosses, and reduction of the fuel quality. Certain processes such as biological- andchemical degradation are responsible for these storage problems. This master?sthesis was carried out at Vattenfall Research and Development AB and is alignedtowards quantifying the biomass losses from short-term storage (1-2 months) ofbark and recovered wood. The biomass was stored in outdoor piles during differentseasons, campaign 1 (summer) and campaign 2 (autumn).

Today?s electrical grid companies understand that better knowledge of and information about their grid can help realize a smart grid network. One way to gain better knowledge and information about the low voltage network is to install measuring equipment on the substation transformer´s secondary low voltage side that measures the low voltage network losses for that specific substation. By doing so, grid companies can, due to the calculation of the low voltage network losses, identify and address issues such as illegal power dissipation, unmeasured power outtakes, and unsatisfied technical documentation for the substations low voltage network.During 2012, Mälarenergi Elnät AB had a total electrical network loss (both medium and low voltage network losses included) of three to four percent of their total distributed electrical volume. Converting this energy volume into a monetary figure this accounts for a loss of around 30 million Swedish crowns.

When harvesteing ley there is always mechanical losses from the harvest machines. During the last years the roundbalers with knives,cutting the material-are more common, This use increase the mechanical losses of material. MATERIALS AND METHODS The roundbaler which used in this test was a Krone Vario Pack 1500 Multi Cut. This roundbaler has 17 knives. The theoretical length of cut was 64 mm. During the test we stretched a rubber tarp under the balechamber and collected the materials which fell down from the balechamber.

The aim of this study examines how two groups of social workers at two workplaces reflect to their own clothes in various work situations. We want to gain an understanding of the variables that affects social workers choice of clothes at work. In a qualitative approach the study is based on two focus group-interviews and four semi structured interviews. Empirically analyzes relate to Pierre Bourdieu?s "la distinction, Ervin Goffman?s "frontstage-backstage", and of Michele Foucault?s power concepts.

There is always a need for more effective ways to store energy in order to reduce the human impact on the environment. One step on the way can be the use of flywheels as kinetic energy storage devices. Low frictional losses are essential for a flywheel to be effective. To minimize these losses active magnetic bearings (AMB) can be used to keep the shaft centered instead of the more conventional ball-bearings. AMBs use actuators and a fast control system that needs correct and noise-free measurement data of the shaft position and the current in the actuators to work properly.This thesis explains the process of constructing power electronics and a current measurement system for active magnetic bearings (AMB).

In Sweden the climate makes it impossible to feed fresh herbage to cattle during many months of the year. During periods when preserved forage must be supplied it is important that this forage is stored in such a way that high quality is retained, both nutritionally and hygienically. Furthermore, it is essential that losses occurring when handling and storing the forage are kept as low as possible. This study compares storage in tower silos, bunker silos, big bags and bales,estimating dry matter losses as well as losses in metabolizable energy and crude protein that occur during storage. The results show that tower silos, bunker silos and big bags, the systems with the largest amount of forage and a long feed out period involve larger losses than bales, which are fed out immediately after being opened. As the feed out rate influences the losses, tower silos and bunker silos should be used during the period of the year when the feed out rate is as high as possible, i.e.