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This thesis describes the development of a micromachine model and associated data acquisition system, which is used to study the improvement of the transient response of a ship's diesel generator set following a severe disturbance. The improvement in response is obtained by the use of transient rotor acceleration as a single extra feedback signal into the excitation and governor systems of the micromachine model. The response of the ship system is predicted by theoretical studies, which use a multiprocessor system to implement a Park's two axes, five winding model of the ship's generator together with the associated automatic voltage regulator and diesel governor models. The optimal feedback gains obtained from the theoretical studies are then used to obtain results from the micromachine system, a comparison between the theoretical and experimental results confirms the conclusion that a significant improvement in the system's transient response is obtained. This improvement is maintained when changes are made to the alternator load and the fault duration, without any alterations to the system feedback gains.

<p>This thesis is an evaluation of a new design concept for statorfeets in Gallejaur hydro power plant. Founder of the work is Vattenfall AB Vattenkraft. During the 70- and 80´s nuclear power began to be phased in to the Swedish grid, which meant that hydropower became an important source of rules. The generators began running in so called intermittent operations instead of basic operations, which meant 300-600 start/stop per year instead of one-ten numbers start/stop per year. In order to deal with the thermal forces that arise at every start and stop suppliers began to mount so called sliding joints, which is to take advantage of these forces and maintain the stator shape. This, however, led to unforeseen consequences.</p><p>The evaluation is a part of a major project, witch started in 2005 with regards to bring down the shutdown time on generators because of the sliding joints, witch are mounted on many older machines today. The sliding joints have tended to stick during operation resulting in serious consequences. Consequences such as cracks in the concrete foundations and stator core buckling causing long shutdown and providing a high level of production lost.</p><p>VG Power who delivered the concept has developed a foot, which ensures that the stator retains its shape when it expands due to the thermal forces arising from the boot and stop of the generator. Analysis and validation of design and calculations made at VG Power shows that the concept is very well dimensioned and can handle the demands that Vattenfall has in the specification. Analysis and validation of operational data from five operational cases also shows that the concept works very well. The concept shows among other things that:</p><ul><li>Movement of the new feet’s follows a clear pattern of movement when starting and stopping the unit.</li><li>The concept is well dimensioned, good margins for safety and stability are provided.</li><li>The concept is suited well for older units.</li><li>The design allows for a safer operation because of reduced maintenance that the concept requires.</li><li>High availability</li></ul><p>Further studies concerning the test of the concept strength is to start a fatigue rig to test whether the concept can handle the intense stress of the micro – movement that occurs during operation. It is important that Vattenfall is examining and doing an analysis on the micro – movement that occurs in the blocks where Vattenfall surveillance system Conwide not allow sufficiently high sampling rate. During a visit to Vattenfall Research And Development in Älvkarleby rust was discovered on the attachment, which requires further consideration of VG Power. It is and important parameter relevant to maintenance and durability.</p>

<p>This thesis describes a method of measuring axial magnetic leakage flux in an operational hydropower generator. Axial magnetic leakage flux is the magnetic flux at the ends of a rotating generator, which goes through the stator parallel to the rotor axis. This flux can cause circulating currents in the stator iron, giving rise to losses, and can in the worst case overheat a generator, causing it to melt down. To measure the axial flux, and how it affects the generator temperature, a measurement system was constructed on behalf of Vattenfall. The system consists of search coil sensors and a signal-processing unit with amplifiers and active filtering.  To confirm the behaviour of the axial leakage flux and the functionality of the measurement system, a test installation was made. The result from the measurement shows how the leakage flux increases when the generator runs in underexcited operation.</p>

With the flourishing development of MEMS, it is possible to combine micro-sensors with micro-actuator and apply to the organ transplant in medical fields or as an embedded sensor on buildings or bridges. Generally batteries is are used as the kinetic energy source, but it involves the issue of recycling. Therefore, development of a self-generator utilizing vibrational source from environment is another better choice. This study succeeds in building up the transform mode of electricity in an electro-magnetic vibration-induced micro-generator. The electricity characteristics of micro-generator are obtained by Mathematical software analysis. MEMs technology can be used to fabricate and assemble the microstructure , planar coils and magnetic films. The analytic results of maximum power and minimum volume by using a mathematics model are achieved. The validity of this model is verified by comparing the theoretical and experiment data from the literature.

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. The sawmill in Venås is afacility of that kind. During the 1920´s two Francis turbines were installed as powersource for the machinery and a small private DC-grid. In 1966 the dam collapsed andthe facility was therefore retired. There is a possibility that the station can once againbe used as a power station to feed electricity to the grid. This will demand a largeamount of work and economic investment. Therefore is both technical andeconomical calculations needed in order to get the facility profitable. This reportincludes such calculations for the Venås station.

This thesis describes a method of measuring axial magnetic leakage flux in an operational hydropower generator. Axial magnetic leakage flux is the magnetic flux at the ends of a rotating generator, which goes through the stator parallel to the rotor axis. This flux can cause circulating currents in the stator iron, giving rise to losses, and can in the worst case overheat a generator, causing it to melt down. To measure the axial flux, and how it affects the generator temperature, a measurement system was constructed on behalf of Vattenfall. The system consists of search coil sensors and a signal-processing unit with amplifiers and active filtering.  To confirm the behaviour of the axial leakage flux and the functionality of the measurement system, a test installation was made. The result from the measurement shows how the leakage flux increases when the generator runs in underexcited operation.

This thesis is an evaluation of a new design concept for statorfeets in Gallejaur hydro power plant. Founder of the work is Vattenfall AB Vattenkraft. During the 70- and 80´s nuclear power began to be phased in to the Swedish grid, which meant that hydropower became an important source of rules. The generators began running in so called intermittent operations instead of basic operations, which meant 300-600 start/stop per year instead of one-ten numbers start/stop per year. In order to deal with the thermal forces that arise at every start and stop suppliers began to mount so called sliding joints, which is to take advantage of these forces and maintain the stator shape. This, however, led to unforeseen consequences. The evaluation is a part of a major project, witch started in 2005 with regards to bring down the shutdown time on generators because of the sliding joints, witch are mounted on many older machines today. The sliding joints have tended to stick during operation resulting in serious consequences. Consequences such as cracks in the concrete foundations and stator core buckling causing long shutdown and providing a high level of production lost. VG Power who delivered the concept has developed a foot, which ensures that the stator retains its shape when it expands due to the thermal forces arising from the boot and stop of the generator. Analysis and validation of design and calculations made at VG Power shows that the concept is very well dimensioned and can handle the demands that Vattenfall has in the specification. Analysis and validation of operational data from five operational cases also shows that the concept works very well. The concept shows among other things that: Movement of the new feet’s follows a clear pattern of movement when starting and stopping the unit. The concept is well dimensioned, good margins for safety and stability are provided. The concept is suited well for older units. The design allows for a safer operation because of reduced maintenance that the concept requires. High availability Further studies concerning the test of the concept strength is to start a fatigue rig to test whether the concept can handle the intense stress of the micro – movement that occurs during operation. It is important that Vattenfall is examining and doing an analysis on the micro – movement that occurs in the blocks where Vattenfall surveillance system Conwide not allow sufficiently high sampling rate. During a visit to Vattenfall Research And Development in Älvkarleby rust was discovered on the attachment, which requires further consideration of VG Power. It is and important parameter relevant to maintenance and durability.

The task in this project is to design a generator for a vertical axis wind turbine withpower rated to 20kW at a wind speed of 10m/s. The project is conducted at theDivision of Electricity at Uppsala University with collaboration from ElectricGeneration AB. The design has just a few moving parts, which decreases maintenancecosts and increases its toughness. The turbine absorbs wind from every direction butits rotation speed ratio is lower than horizontal axis wind turbines. It means that thegenerator must be bigger and therefore more expensive. Price is an importantcriterion for the generator. Neodymium magnets are expensive so the amount of thismaterial must be limited.Several designs have been simulated but one final design has proven the mostpromising. It fulfills all specifications such as efficiency above 95%, 20kW outputpower and it also has a relatively low amount of hard magnetic material.A design with a single row of cables per slot was decided upon to eliminate heatpockets between cable rows, which can occur in designs with two cable rows perslot. It would be interesting to study designs with two or more cable rows per slot, asit could lead to a smaller and more efficient machine.

As the complexity of System-on-a-Chip (SoC) designs increases, embedded memory components gradually occupy a significant portion of the total area cost, and the reusable memory Intellectual Property (IP) design becomes a critical issue. In this thesis, an automatic cache generator is developed which can be easily integrated into the current cell-based design flow. The generated cache contains both hard IP and soft IP. The storage array circuits are implemented as hard IP to reduce the area cost. The cache control unit is realized as soft IP. The hard IP of the core memory circuits mainly store data and tag information. The implementations of tag arrays can be divided into two categories: RAM-tag design and CAM (Content Addressable Memory)-tag design. We adopt the CAM-tag style in our cache design because CAM cells have the functions of storage as well as data-matching, and thus can be easily used to realize the tag function in cache. The soft IP of cache controller implements the different writing strategies and block replacement methods. The input parameters of the cache generator include cache size, block size, information on set-associativity, writing strategy, replacement methods, etc. The output of the cache generator contains the RTL code for the soft IP and other necessary Models for the hard IP so that the generated cache can be mixed with other pure cell-based design modules during synthesis and placement-and-routing.