Application And Setting Notes - Siemens 7SJ82 Manual

Protection and Automation Functions
6.3 Overcurrent Protection, Phases
Values
Iph:C
You can find the parameter Rated current in the FB General of function groups where the Overcurrent
protection, phases – advanced function is used.
If the parameter Enable filter is set to no, the functional measured values are shown as ---.
6.3.3.2

Application and Setting Notes

Parameter: Enable filter
•
Default setting (_:1) Enable filter = no.
With the parameter Enable filter, you set whether the Filter is enabled.
Parameter Value
yes
no
Parameter: h(0), h(1), h(2), h(3), h(4)
•
Default setting (_:2) h(0) = 0.000
•
Default setting (_:3) h(1) = 0.000
•
Default setting (_:4) h(2) = 0.000
•
Default setting (_:5) h(3) = 0.000
•
Default setting (_:6) h(4) = 1.000
With the default value of the coefficients, the filter has no effect and no gain is applied.
If the filter shall be applied to adapt the RMS value calculation to a specific protection object such as a reactor,
the reactor manufacturer has to provide the required amplitude response (gain factors) for the reactor. To
determine the coefficients h(0) to h(4) for the FIR filter, you must enter the gain factors into the auxiliary PC
tool which is available in the SIPROTEC download area. The 5 required coefficients are generated by the tool.
They have to be entered manually as settings to configure the filter. The amplitude attenuation of higher
frequencies due to the anti aliasing filter of the device is automatically taken into account and compensated
by the filter.
To only compensate the attenuation of higher frequencies by the device, set the following coefficients in the
filter.
Rated Frequency
50 Hz
60 Hz
326
Description
Gained RMS measured
value of current C
Description
If gained RMS values should be used in one of the protection stages, set
parameter Enable filter = yes.
If no gained RMS values are needed, set the parameter Enable filter =
no.
Filter Coefficients for Only Compensating the Device Amplitude Attenu-
ation
h(0) = -0.002
h(1) = -0.012
h(2) = 0.045
h(3) = -0.110
h(4) = 1.151
h(0) = -0.005
h(1) = -0.020
h(2) = 0.058
h(3) = -0.128
h(4) = 1.170
Primary Secondary
kA A
SIPROTEC 5, Overcurrent Protection, Manual
% Referenced to
Parameter Rated current
C53000-G5040-C017-8, Edition 07.2017