Evaluation of new earth fault localization methods by earth fault experiments

This paper presents results of earth fault field tests in a medium voltage network using new earth fault detection methods. An interpretation of voltage and current signals measured at the area of influence is provided. The pros and cons of different algorithms in different grid constellations are elaborated. The results show that new detection algorithms can provide stable directional decisions even in combination with unconventional transducers. This information is very important for the grid operator. With reliable information of the earth fault direction, especially in rural areas, the field engineers can be deployed more efficiently. Another focus of the tests was on the earthing system. At special grid components, such as dead end poles with cable link, the earth potential rise (EPR) was measured. With the signals measured throughout the tests, results of previously taken measurements to verify the earthing system could be confirmed.