Siemens 6MD85, Manual

Page: 689 / 1256

No. Information Data Class
(Type) Type
_:8161:59 Inverse-T 1:Disk emulation running SPS O
_:8161:55 Inverse-T 1:Pickup ACD O
_:8161:300 Inverse-T 1:Direction ACD O
_:8161:56 Inverse-T 1:Operate delay expired ACT O
_:8161:57 Inverse-T 1:Operate ACT O
Stage with User-Defined Characteristic Curve
Description
The structure of this stage is identical to that of the advanced stage with directional inverse-time characteristic
curve (
7.6.4.1 Description ). The only difference is that you can define the characteristic curve as desired.
User-Defined Characteristic Curve
With the directional, user-defined characteristic curve, you can define the operate curve point by point using
up to 30 value pairs of current and time. The device uses linear interpolation to calculate the characteristic
curve from these values. You can also define a dropout characteristic curve if you wish.
Pickup and Dropout Behaviors with User-Defined Characteristic Curve
When the input variable exceeds the threshold value by 1.1 times, the characteristic curve is processed.
An integrating method of measurement totalizes the weighted time. The weighted time results from the char-
acteristic curve. For this, the time that is associated with the present current value is determined from the
characteristic curve. Once the weighted time exceeds the value 1, the stage operates.
When the measured value falls short of the pickup value by a factor of 1.045 (0.95 x 1.1 x threshold value),
the dropout is started. The pickup will be indicated as clearing. You can influence the dropout behavior via
setting parameters. You can select between instantaneous dropout (totalized time is deleted) or dropout
according to the characteristic curve (reduction of totalized time depending on the characteristic curve). The
dropout according to characteristic curve (disk emulation) is the same as turning back a rotor disk. The
weighted reduction of the time is initiated from 0.9 of the set threshold value.
[dwocpken-140611-02.tif, 2, en_US]
Figure 7-96 Pickup and Dropout Behaviors when Using a Directional User-Defined Characteristic Curve
7.6.6
7.6.6.1
Protection and Automation Functions
7.6 Directional Overcurrent Protection, Phases
SIPROTEC 5, High-Voltage Bay Controller, Manual 689
C53000-G5040-C015-9, Edition 11.2017