Improved algorithm of the earth fault distance measuring units

Distance protection is the most common protection of electric power transmission lines. However, the distance measuring units operation during earth faults with the fault resistance is not always effective. The earth fault distance protection measuring unit algorithm on the base of the precise simulation of the earth fault for the protective object is developed. The analysis of the distance measuring unit operation by using the new and classical algorithms in the different earth fault regimes with different values of fault resistance is presented. The obtained estimations of distance protection measuring unit operation show, that the developed algorithm is more effective, then the classical algorithm during the earth faults with the fault resistance.