| 摘要 |
The invention relates to a method in the earth fault protection of a three-phase electrical network. In the method the total current (10) is determined continuously in a measurement point (17) of the electrical network (10). In the method an earth fault (16) is detected, after which the necessary measures are performed. In the method the return current (Ip) caused by the earth fault is determined, which is eliminated from the total current (10). In addition, by elimination from the total current (10) the earth fault current (Is) is determined, from which, on the basis of the location of the earth fault (16) the earthing voltage (Urn) is determined, on the basis of which the earth fault (16) is detected and the necessary measures performed. |
