Calculation of pressure rise in electrical installations due to internal arcs considering SF6-air mixtures and arc energy absorbers

Existing pressure calculation methods, which are able to determine pressure rise due to internal arcing, are in general reliable. For practical applications, two methods are of importance, the so-called CFD calculation method, which provides spatially resolved results, and the standard calculation method which delivers spatially averaged values. However, the application range of these methods is limited. This is especially true if SF6-air mixtures in SF6-insulated switchgear have to be considered or if arc energy absorbers are installed. In this thesis, these problems are treated. The key point of modelling SF6-air mixture flows of changing composition is the generation and treatment of reliable gas data. The main focus of considering arc energy absorber is the modelling of its effects. For this purpose, heat absorption and flow resistance are treated separately. In order to describe both effects simultaneously, existing and improved model approaches are evaluated and appropriate model combinations are proposed. SF6-air mixtures and the effect of arc absorbers are implemented in both calculation methods for the first time with reliable gas data. Special care is taken on data handling and the modifications of the equation systems. The inclusion of the effect of absorbers is achieved by considering heat sinks and friction forces. Both calculation methods are validated by comparing measurements in different arrangements with calculation results.