Stage with Definite-Time Characteristic Curve
Stage Description
Logic of a Stage
[logiknsp-070312-01.tif, 2, en_US]
Figure 6-154
Logic Diagram of the Stage Negative-Sequence Protection with Definite-Time Characteristic
Curve
Method of Measurement
The fundamental phasors are calculated from the 3-phase phase currents. Based on this, the negative-
sequence system and the positive-sequence system are calculated. Following this, the negative-sequence
current is normalized to the reference current. The selection of the reference current is made in the FB
General.
Blocking of the Stage
When blocked, the picked-up protection stage will drop out.
Blocking the stage is possible externally or internally via the binary input signal >Block stage.
Blocking of Tripping via the Device-Internal Inrush-Current Detection Function
With the Blk. w. inrush curr. detect. parameter, you can define whether tripping of the stage
should be blocked when a threshold value is exceeded due to an inrush current. In case of a blocking, the
stage picks up. The start of the time delay and tripping are however blocked. The stage signals this by way of a
6.17.4
6.17.4.1
Protection and Automation Functions
6.17 Negative-Sequence Protection
636 SIPROTEC 5, Overcurrent Protection, Manual
C53000-G5040-C017-8, Edition 07.2017
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