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745 Uppsatser om Ground fault - Sida 1 av 50

Automation i Distributionsnät

As a part of Göteborg Energi?s work towards a smarter electric grid, the company has chosen to investigate the possibilities of automation in their middle voltage grid. In Europe, there are example cases where these technologies already are installed which many articles on the CIRED conference 2011 proved. Netcontrol Oy in Finland has, together with Tekla, created an automated SCADA system that Vattenfall in Finland today uses. The grid mainly consists of 10 kV open loop fed city grid and this automation is mainly designed for this type of grid.

Felisolering av hytt- och chassikomponenter på tunga fordon

This master of science thesis is focusing on how the fault handling on hardware connected toa control unit on a Scania vehicle is working. To the hardware counts buttons levers, sensorsand CAN. The work has been concentrated upon how the fault handling is working and if it ispossible to find any new fault modes.The control unit that has been studied is called the Coordinator and is the core in Scanias threenetworks of control units. The Coordinators work is to transmit messages between the threenetworks and to process signals from buttons, levers and sensors. The values is then usedinternally or is sent to other control units on the CAN networks.

Hur ökad fukthalt påverkar pannor

This report is a description of a developed educational simulator over rail vehicles and its components. The simulator is a hardware-based prototype over a door system on rail vehi- cles. System specialists and technicians will use the prototype. The Simulator should give the user a technical demonstration on how components work in a door system. The proto- type consists of motor, switch, relay and sensor.

Utbildningssimulator av funktioner i spa?rfordon : Ha?rdvarusimulator med felso?kning pa? do?rrsystem

This report is a description of a developed educational simulator over rail vehicles and its components. The simulator is a hardware-based prototype over a door system on rail vehi- cles. System specialists and technicians will use the prototype. The Simulator should give the user a technical demonstration on how components work in a door system. The proto- type consists of motor, switch, relay and sensor.

Hjälpkraftsystem med två lågspänningsnivåer

Because of increasing demand of power on Malmbanan the capacity of the existing wires which supply the trains must be increased. This increases the stress on the existing poles and for this reason the system for supplying the loads along the railway is to be removed from the poles and be replaced by some other system. This thesis is a study on a two-level low voltage (1 kV and 0.4 kV) electrical system with the aim to investigate if it can be an alternative to the system used today taking into account the voltages, fault currents and costs.In this thesis the following tasks have been performed:? Gathering of data? Description of basic theory? Loadow and fault current calculations of the system with MATLAB? Life Cycle Cost estimate of the system? Analysis and conclusions from the resultsThe results show that the new system can be an alternative to replace today's system. The simulations and calculations show that the voltage drop is at an acceptable level and that the fault currents are large enough to supply a safe disconnection if a fault occurs at the far end of the system..

Statuskontroll av Paradisskolans elektriska belastning

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.

Ett flervariabelt feldetekteringssystem för övervakning av bärlagertemperaturen i vattenkraftturbiner

The purpose of this thesis work was to develop an automatic fault detection system for surveillance of bearing temperature in hydropower turbines. The parameters used except the bearing temperature were cooling water temperature and cooling water flow. A simple static model based on data sampled every minute was developed to estimate the bearing temperature. Then a detector for detection of change in bearing temperature based on the CUSUM-algorithm was designed. Since the amount of data was very small the developed model was too uncertain to be used in a working system.The designed fault detection system showed to work well for the available data.

Bättre åtkomst till avverkningstrakter med anpassat marktryck från avverkningsmaskinerna

The global climate-change means increasing mean-temperature and higher precipitation in Sweden, which leads to shorter periods of frozen ground in the forest. At the same time the harvesting machines are getting bigger and more powerful. The forest industry aim at an even wood flow, and the ground damage has to be as low as possible. The two biggest causes for ground-damage is the bearing capacity of the forest ground and the ground-pressure of the harvesting machines. The aim of this study was to find out some rules for the machine choice considering ground pressure, when harvesting on ground with low bearing capacity.A field study, using a Valmet 890.3 forwarder, was carried out where different ground pressures and their effect on the ground were tested on two different types of ground.Additionally, an inventory of damaged harvesting grounds was made.

Simulering av vindkraftverk och närliggande elnät vid Risholmen i Göteborg i SimPowerSystems

With background in the rapidly growing need to find solutions for sustainable energy production and the increasing interest for wind power, this report was written. With take-off point from the wind power plant Big Glenn, which has been built in the harbour of Gothenburg, a model of the adjacent power grid has been created in Simulink/SimPowerSystems. Parameters for the power grid and its components has been provided by Göteborg Energi Nät, that has also been the supplier of measurement data of produced power, the power need from loads in the vicinity, voltage levels, current values and also the variation of power factor at the wind power plant.The SimPowerSystems model has been used to perform simulations of power flow in the grid. These simulated values have then been compared to the measured values to verify the functionality of the model. Further, the model has been used to perform simulations of a grid fault, which causes a voltage drop.

VSM och 16 förluster

With background in the rapidly growing need to find solutions for sustainable energy production and the increasing interest for wind power, this report was written. With take-off point from the wind power plant Big Glenn, which has been built in the harbour of Gothenburg, a model of the adjacent power grid has been created in Simulink/SimPowerSystems. Parameters for the power grid and its components has been provided by Göteborg Energi Nät, that has also been the supplier of measurement data of produced power, the power need from loads in the vicinity, voltage levels, current values and also the variation of power factor at the wind power plant.The SimPowerSystems model has been used to perform simulations of power flow in the grid. These simulated values have then been compared to the measured values to verify the functionality of the model. Further, the model has been used to perform simulations of a grid fault, which causes a voltage drop.

Nätverksövervakning för IT miljön

Denna rapport handlar om Övervakning i en IT miljö som täcker både nätverk och system. Denna rapport inriktar sig på Fault Management och Performance Management..

Vibrationsproblem i närliggande konstruktioner i samband med markarbete

Ground work like blasting, piling and excavation has always had a great influence during the planning phase of a construction project since it can cause damages on adjacent buildings and have severe economic consequences. This thesis deals with how vibrations caused by ground work influence near-by buildings and what methods geotechnicians and construction entrepreneurs use to handle these risks.The purpose of this thesis is to explain risk management in relation to ground work. In order to achieve this I have used a qualitative method by interviewing a geotechnician and a ground work contractor who possess knowledge and experience useful to this thesis. The result shows that vibrations from ground work spread through the ground as seismic waves that cause displacements and packing in the ground visible in adjacent buildings as cracks and subsidence damages. Geotechnicians study ground work vibrations by means of ground investigations and experience from previous projects in order to produce a risk analysis that entrepreneurs can use to reduce damages.

Mätutrustning för kosmisk strålning

The purpose with this examination is to build a measureequipment to AerotechTelub AB (AT), who will registrate fault in SRAM-memory in contact with cosmic radiation. The equipment will be created around developcard from Memec Design with FPGA from Xilinx. The logic in the FPGA will be implemented with the hardwaredescribed language VHDL. The SRAM-memory that will be tested is build in CMOS-teknologi. The memorycells will be loaded with a predecided bitpattern.

Optimering av testning av säkerhetskritiska funktioner

Inom industrin används olika testmetoder för att uppnå hög kvalitet i mjukvarukontrollerade system. Kvalitetskraven är särskilt höga för säkerhetskritiska system t.ex. styr- och reglersystem i fordon. I det här examensarbetet används två analysmetoder (Fault Mode and Effects Analysis och Fault Tree Analysis) för att ta fram ett nytt säkerhetstest för ett broms- och växlingssystem som Scania tillverkar. Det studeras även hur formella metoder kan användas för att ytterligare öka kvalitet ochh tillförlitlighet.

Product/Service-Systems ? en litteratur undersökning för att definiera och differentiera forskningsområdet

Inom industrin används olika testmetoder för att uppnå hög kvalitet i mjukvarukontrollerade system. Kvalitetskraven är särskilt höga för säkerhetskritiska system t.ex. styr- och reglersystem i fordon. I det här examensarbetet används två analysmetoder (Fault Mode and Effects Analysis och Fault Tree Analysis) för att ta fram ett nytt säkerhetstest för ett broms- och växlingssystem som Scania tillverkar. Det studeras även hur formella metoder kan användas för att ytterligare öka kvalitet ochh tillförlitlighet.

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