| 摘要 |
According to the invention, provided are a method and a device (20) for directional detection of an earth fault (10) in a multi-phase power system (1), based on the detection after the fault (10) occurs and on the number (N) of zero-crossing points of a zero sequence current (I) which is generated due to high-frequency interference of scattered elements of lines and cables (4) of the power system (1). The current (I) and the comparison between the number of zero-crossing points (N) thereof relative to the differential (d*) of time and a predetermined threshold value (Z, dZ) allow the fault to be positioned at the load side or the line side of the device (20), without adopting voltage measurement but a single current sensor (12). |
