| 摘要 |
PCT No. PCT/DE95/01372 Sec. 371 Date Aug. 11, 1997 Sec. 102(e) Date Aug. 11, 1997 PCT Filed Sep. 26, 1995 PCT Pub. No. WO96/10857 PCT Pub. Date Apr. 11, 1996A current differential protection arrangement for an electric power supply unit with a measured value pre-processing device and an analysis device that checks on the basis of a predefined dependence of a differential current on a stabilizing current (response characteristic curve) to determine whether the differential and stabilizing current values thus formed are in a blocking range or a triggering range, where an additional stabilization range is present in the blocking range. To avoid fixed-time blocking after an external fault with transformer saturation with such a protection arrangement, the analysis device in a stabilizing circuit contains a testing arrangement which checks the current values thus formed to determine whether they describe a point in the additional stabilization range. If this is the case, a blocking signal is produced, which activates the blocking device downstream from the testing arrangement. When a first point of the current values is subsequently detected outside the additional stabilization range, a timing element that is connected at the output to a resetting input of the blocking device is set.
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