Search for dissertations about: "transformer diagnostics"
Showing result 1 - 5 of 9 swedish dissertations containing the words transformer diagnostics.
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1. Magnetizing Currents in Power Transformers : Measurements, Simulations, and Diagnostic Methods
Abstract : This thesis demonstrates a method for transformer core diagnostics. The method uses the no-load current of the transformer as an indicator, and gives different characteristic signatures for different types of faults or defects. Using the no-load current for the diagnostic gives high sensitivity. READ MORE
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2. On methods of measuring magnetic properties of power transformers
Abstract : The core of a power transformer can weigh hundreds of tons, and represents a significant part of the total ownership cost of the transformer, in terms of both the construction cost and of the monetary cost of losses. It is therefore desirable to have a method of diagnosing the core to ensure optimal performance, and to enable the operator to plan repairs of damaged or defective cores. READ MORE
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3. Online power transformer diagnostics using multiple modes of microwave radiation
Abstract : In the present thesis, we propose and investigate a new approach to diagnose the effects of the various degradation mechanisms, including thermal degradation at hot spots, winding deformations due to the mechanical forces from short circuit currents, partial discharges due to local electric field surges, and increased moisture levels in the cellulose insulation due to decomposition, that affect electric power transformers during their normal operation in an electric power grid.Although the proposed diagnostics method can in principle be used to detect various degradation mechanisms mentioned above, we focus in the present thesis on mechanical deformations of transformer winding structures. READ MORE
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4. Partial Discharge Signatures of Defects in Insulation Systems Consisting of Oil and Oil-impregnated Paper
Abstract : Partial discharge measurement is a common method for monitoring and diagnostics of power transformers, and can detect insulation malfunctions before they lead to failure. Different parameters extracted from the measured PD activity can be correlated to the PD source, and as a result it is possible to identify the PD source by analyzing the PD activity. READ MORE
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5. Condition-based Failure Rate Modelling for Individual Components in the Power System
Abstract : The electrical power grid is one of the most important infrastructures in the modernsociety. It supplies industrial and private customers with electricity and supportsother critical infrastructures such as the water supply. Thus, it is significant that the power grid is a reliable system. READ MORE
