Functions
2.15 Flexible Protection Functions
SIPROTEC, 7SK80, Manual
E50417-G1140-C344-A5, Release date 11.2012
225
Section 2.16 gives an application example of the function „reverse power protection“.
The maximum 20 configurable protection functions operate independently of each other. The following descrip-
tion concerns one function; it can be applied accordingly to all other flexible functions. The logic diagram 2-84
illustrates the description.
Function Logic
The function can be switched ON and OFF or, it can be set to Alarm Only. In this status, a pickup condition
will neither initiate fault recording nor start the trip time delay. Tripping is thus not possible.
Changing the Power System Data 1 after flexible functions have been configured may cause these functions
to be set incorrectly. Message (FNo.235.2128 „$00 inval.set“) reports this condition. The function is in-
active in this case and function's setting has to be modified.
Blocking Functions
The function can be blocked via binary input (FNo. 235.2110 „>BLOCK $00“) or via local operating terminal
(„Control“ -> „Tagging“ -> „Set“). Blocking will reset the function's entire measurement logic as well as all
running times and indications. Blocking via the local operating terminal may be useful if the function is in a
status of permanent pickup which does not allow the function to be reset. In context with voltage-based char-
acteristics, the function can be blocked if one of the measuring voltages fails. Recognition of this status is either
accomplished by the relay's internal „Fuse-Failure-Monitor“ (FNo. 170 „VT FuseFail“; see section 2.10.1)
or via auxiliary contacts of the voltage transformer CB (FNo. 6509 „>FAIL:FEEDER VT“ and FNo. 6510
„>FAIL: BUS VT“). This blocking mechanism can be enabled or disabled in the according parameters. The
associated parameter BLK.by Vol.Loss is only available if the characteristic is based on a voltage measure-
ment.
When using the flexible function for power protection or power monitoring, it will be blocked if currents fall below
0.03 I
Nom
.
Parameter BLK f out of r allows you to specify whether the protection function is blocked if the measured
power frequency is outside the operating range of the function (25 Hz to 70 Hz).
Power P Real power Reverse power protection
Power protection
32R, 32, 37 X X
Q Reactive power Power protection 32 X X
cos ϕ Power factor Power factor 55 X X
Binary input – Binary input Direct coupling without phase refer-
ence
Characteris-
tic Group
Characteristic / Measured Quantity Protective Function ANSI No. Mode of Operation
Three-
phase
Single-
phase
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