Handling of Ground Fault in Distribution Networks: Regarding the Field Test Taken by SINTEF in 2005

Abstract

SUMMARY The main subject of this master thesis is the study of single phase to ground fault in a given distribution network. SINTEF took part in a field test, which was done in 2005. After the field test being done, a report was elaborated. The report became the main reference of this document. The purpose of this work is the creation of a PSCAD model that can be an authentic representative of the tested distribution network in 2005. Moreover, a detection and location method for single phase to ground faults is tested in order to find any limitation in it and to be an important part of the validation of the model. The model was created from a variety of given information from SINTEF, a frequency line dependent model was used as a part of the overhead lines representation, in order to have a model as close as possible from the real distribution network behaviour. A deep study of resonant grounding was made in this document, due to its direct involvement in the single phase to ground faults measurements in the field test. The main focus of the model were related to the magnitude and the orientation of the zero sequence currents, the latest ones are considered as the most important variable of study throughout this work. The validation of the proposed model was granted by the important variables consistency between the field test and the given results from the simulations. The field test results were gotten from the report elaborated by SINTEF. The QU diagrams, which were gotten from the simulations, gave the expected behaviour according to the field test. Therefore, the proposed location and detection method for single phase to ground faults gave an approval to the PSCAD model presented in this document as an authentic representative of the distribution network tested in 2005.