Functions
2.1 General
SIPROTEC, 7RW80, Manual
C53000-G1140-C233-1, Release date 10.2010
31
The settings Vab, Vbc or Vab, Vbc, Vx or Vab, Vbc, VSyn or Vph-g, VSyn do not allow determining
the zero sequence voltage. The associated protection functions are inactive in this case.
The table gives an overview of the functions that can be activated for the corresponding connection type (de-
pends also on the ordering number). The functions which are not shown are available for all connection types.
Table 2-1 Connection Types of the Voltage Transformers
Measured values, which due to the chosen voltage connection cannot be calculated, will be displayed as dots.
The Appendix provides some connection examples for all connection types at A.3.
Nominal Values of Voltage Transformers (VTs)
At addresses 202 Vnom PRIMARY and 203 Vnom SECONDARY, information is entered regarding the primary
nominal voltage and secondary nominal voltage (phase-to-phase) of the connected voltage transformers.
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 V
N
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:
the factor V
ph
/V
N
(secondary voltage, address 206 Vph / Vdelta) must be set to 3/ √3 = √3 = 1.73 which
must be used if the V
N
voltage is connected. For other transformation ratios, i.e. the formation of the displace-
ment voltage via an interconnected transformer set, the factor must be corrected accordingly.
Please take into consideration that also the calculated secondary V
0
-voltage is divided by the value set in
address 206. Thus, even if the V
0
-voltage is not connected, address 206 has an impact on the secondary op-
erational measured value V
N
.
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 calculated the operational measured value of the „sec-
ondary voltage V
N
“.
Connection type Synchronization
Van, Vbn, Vcn No
Vab, Vbc, VGnd No
Vab, Vbc No
Vab, Vbc, Vx No
Vab, Vbc, VSyn Yes
Vph-g, VSyn Yes
To Next Page
Loading...
Need help?
General