Condition assessment of distribution grids combining measurement methods and theory of evidence

Summary

The present paper deals with systematic approaches for condition assessment of medium-voltage (MV) and high-voltage (HV) assets in order to support asset management of distribution grids. Therefore, modern approaches using minimally invasive measurements and the theory of evidence are demonstrated. In this context the paper shows several practical applications for various types of MV-substations and gas-insulated HV-substations. Thereby, it especially observes the differences of the used measurements regarding different voltage levels. An overview of meaningful measurements applied during service is given, which makes the condition assessment more reliable without spending too much effort for condition assessment. In addition the validity of condition assessment results is determined by the use of the theory of evidence. Thus, each measurement has a different impact on the reliability of the evaluation result, which is focussed in this paper. The reliability generally differs against the available assessment data, which makes them hard to compare. However, the paper shows how to solve that problem and to determine easy comparable evaluation results. Finally, the main benefits of those modern assessment approaches are observed regarding the practical experience of thousands of MV- and HV-substations.

Additional informations

Keywords

acoustic partial discharge detection, thermography, earth-loop-testing, measurement methods, uncertainty, theory of evidence, distribution grids, condition assessment