Values Description Primary Secondary % Referenced to
Iph:C Gained RMS measured
value of current C
kA A Parameter Rated current
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 ---.
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 Description
yes
If gained RMS values should be used in one of the protection stages, set
parameter Enable filter = yes.
no
If no gained RMS values are needed, set the parameter Enable filter =
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
Filter Coefficients for Only Compensating the Device Amplitude Attenu-
ation
50 Hz h(0) = -0.002
h(1) = -0.012
h(2) = 0.045
h(3) = -0.110
h(4) = 1.151
60 Hz h(0) = -0.005
h(1) = -0.020
h(2) = 0.058
h(3) = -0.128
h(4) = 1.170
6.3.3.2
Protection and Automation Functions
6.3 Overcurrent Protection, Phases
326 SIPROTEC 5, Overcurrent Protection, Manual
C53000-G5040-C017-8, Edition 07.2017
To Next Page
Loading...
