2 resultados para specific dynamic action
em Doria (National Library of Finland DSpace Services) - National Library of Finland, Finland
Resumo:
In distributed energy production, permanent magnet synchronous generators (PMSG) are often connected to the grid via frequency converters, such as voltage source line converters. The price of the converter may constitute a large part of the costs of a generating set. Some of the permanent magnet synchronous generators with converters and traditional separately excited synchronous generators couldbe replaced by direct-on-line (DOL) non-controlled PMSGs. Small directly networkconnected generators are likely to have large markets in the area of distributed electric energy generation. Typical prime movers could be windmills, watermills and internal combustion engines. DOL PMSGs could also be applied in island networks, such as ships and oil platforms. Also various back-up power generating systems could be carried out with DOL PMSGs. The benefits would be a lower priceof the generating set and the robustness and easy use of the system. The performance of DOL PMSGs is analyzed. The electricity distribution companies have regulations that constrain the design of the generators being connected to the grid. The general guidelines and recommendations are applied in the analysis. By analyzing the results produced by the simulation model for the permanent magnet machine, the guidelines for efficient damper winding parameters for DOL PMSGs are presented. The simulation model is used to simulate grid connections and load transients. The damper winding parameters are calculated by the finite element method (FEM) and determined from experimental measurements. Three-dimensional finite element analysis (3D FEA) is carried out. The results from the simulation model and 3D FEA are compared with practical measurements from two prototype axial flux permanent magnet generators provided with damper windings. The dimensioning of the damper winding parameters is case specific. The damper winding should be dimensioned based on the moment of inertia of the generating set. It is shown that the damper winding has optimal values to reach synchronous operation in the shortest period of time after transient operation. With optimal dimensioning, interferenceon the grid is minimized.
Resumo:
A rapidly changing business environment has necessitated most small and medium sized enterprises with international ambitions to reconsider their sources of competitive advantage. To survive in the face of a changing business environment, firms should utilize their dynamic organizational capabilities as well as their internationalization capabilities. Firms develop a competitive advantage if they can exploit their unique organizational competences in a new or foreign market and also if they can acquire new capabilities as a result of engaging in foreign markets. The acquired capabilities from foreign locations enhance the existing capability portfolio of a firm with a desire to internationalize. The study combined the research streams of SME organizational dynamic capability and internationalization capability to build a complete picture on the existing knowledge. An intensive case study was used for empirically testing the theoretical framework of the study and compared with the literature on various organizational capability factors and internationalization capabilities. Sormay Oy was selected because it is a successful medium sized company operating in Finland in the manufacturing industry which has a high international profile. In addition, it has sufficient rate of growth in sales that warrants it to engage internationally in matters such as, acquisitions, joint ventures and partnerships. The key findings of the study suggests that, medium sized manufacturing firms have a set of core competences arising from their organizational capabilities which were identified to be employee know how and relationship with stakeholders which aid the firm in its quest for attaining competitive advantage, ensuring production flexibility and gaining benefits present in a network. In addition, internationalization capabilities were identified under both the RAT test and CAT test whereby the primary findings suggests that, firms that outperform their competitors produce products that meet specific customer and country requirements, foresee the pitfalls of imitation brought about by the foreign local companies and members of a particular network through joint ventures, acquisitions or partnerships as well as those firms that are capable to acquire new capabilities in the foreign markets and successfully use these acquired capabilities to enhance or renew their capability portfolio for their competitive advantage. Additional significant findings under internationalization capabilities were discovered whereby, Sormay Oy was able to develop a new market space for its products despite the difficult institutional environment present in Russia.