Siemens 7SC80 Manual page 55

NOTE
i
i
Select the setting values carefully in order to not corrupt the results due to saturation, for example.
The large measuring range of the voltage input can cause increased tolerances in connection with an
unfavorable transformation ratio with too small voltages.
NOTE
i
i
For LoPo/LPS devices, to ensure the stated accuracy, you need to take one of the following actions:
•
Apply additional magnetic shielding measures to the devices.
•
Reduce the magnetic influence.
Transformation Ratio of Voltage Transformers (VTs)
Address 206 Vph/Vdelta informs the device of the adjustment factor between the phase voltage and the
displacement voltage. This information is relevant for the processing of ground faults (in grounded systems
and ungrounded systems), for the operational measured value VN and measured-variable monitoring.
If the voltage transformer set provides open delta windings and if these windings are connected to the device,
this must be specified accordingly in address 213 (see above margin heading "Voltage Connection"). Since the
voltage transformer ratio is normally as follows:
[uebersetzung-spannungswandler-020313-kn, 1, en_US]
the factor V /V
ph
be used if the V
voltage via an interconnected transformer set, the factor must be corrected accordingly.
Please take into consideration that also the calculated secondary V
address 206. Thus, even if the V
operational measured value V
If Vab, Vbc, VGnd is selected as voltage connection type, parameter Vph/Vdelta is used to calculate the
phase-to-ground voltages and is therefore important for the protection function. With voltage connection type
Van, Vbn, Vcn, this parameter is used only to calculate the operational measured value of the "secondary
voltage V ".
N
Phase Angle Correction of the Voltage Transformers
At address 344 VT PhAng COR A, you can enter the phase angle correction for the phase A voltage trans-
former.
At address 357 VT PhAng COR B, you can enter the phase angle correction for the phase B voltage trans-
former.
At address 358 VT PhAng COR C, you can enter the phase angle correction for the phase C voltage trans-
former.
At address 345 VT Vx PhAng COR, you can specify the phase angle correction for the 4th voltage trans-
former Vx.
Amplitude Correction of the Voltage Transformers
At address 346 VT A AMPL COR, address 347 VT B AMPL COR and address 348 VT C AMPL COR, you can
enter the phase-specific correction factor for the voltage transformer amplitudes. At address 349 Vx AMPL
COR, enter the correction factor for the 4th voltage transformer Vx.
This allows system-related deviations of voltage measurement to be compensated for.
SIPROTEC Compact, 7SC80, Manual
E50417-G1140-C486-A8, Edition 07.2017
(secondary voltage, address 206 Vph/Vdelta) must be set to 3/ √3 = √3 = 1.73 which must
N
voltage is connected. For other transformation ratios, i.e. the formation of the displacement
N
-voltage is not connected, address 206 has an impact on the secondary
0
.
N
-voltage is divided by the value set in
0
Functions
2.1 General
55