Sökning: "streamer"
Visar resultat 1 - 5 av 21 avhandlingar innehållade ordet streamer.
1. Numerical Simulations of Long Spark and Lightning Attachment
Sammanfattning : The research work presented here is concerned with numerical simulations of two different electrical phenomena: Long gap electrical discharges under switching impulses and the lightning attachment process associated with positive upward leaders. The development of positive upward leaders and the progression of discharges in long gaps are attributable to two intertwined physical phenomena, namely, the leader channel and the streamer zone. LÄS MER
2. Cellulose-based electrical insulation materials : Dielectric and mechanical properties
Sammanfattning : The reliability of the generation and distribution of electricity is highly dependent on electrical insulation and is essential for the prosperity of our society and a ubiquitous part of our everyday life. The present study shows how some important material properties affect the electrical properties of cellulose-based electrical insulation systems which are used together with mineral oil in high-voltage transformers. LÄS MER
3. Characteristics of streamer discharges in air and along insulating surfaces
Sammanfattning : Power quality is dependent on the dielectric properties of the insulators used throughout the power generation and power transmission utilities. Knowledge of the pre-discharge stage associated with the electrical breakdown across outdoor insulators is essential if one is to improve the performance of these insulators under various electrical and environmentalconditions. LÄS MER
4. Numerical modelling of positive electrical discharges in long air gaps
Sammanfattning : This dissertation deals with research on the numerical modelling of electrical discharges in laboratory long air gaps excited with positive switching impulses. It begins with the preliminary work of several scientists during the last decades, making a detailed analysis of different approaches for modelling all the stages in a full discharge. LÄS MER
5. Computational framework for studying charge transport in high-voltage gas-insulated systems
Sammanfattning : Increasing demands in electric energy stimulates a shift in functional requirements to power distribution networks and pushes equipment manufacturers to develop highly optimized products where high rated parameters (e.g., energy, voltages) are combined with reduced geometrical dimensions of components. LÄS MER