GE MiCOM P40

DDB
Vsc1 Select x1
DDB
Vsc1 Select 1x Vsc1 Selection
0 1 Vcs2
1 0 Vcs3
1 1 Unused
The selection of voltage Vsc2 is controlled by the combined status of two DDBs, Vsc2 Select x1 and Vsc2 Select 1x
as shown in the following table.
DDB
Vsc2 Select x1
DDB
Vsc2 Select 1x Vsc2 Selection
0 0 Vcs2
0 1 Vcs3
1 0 Vcs1
1 1 Unused
The selected single-phase voltages are only displayed when VT Switch Mode is enabled.
4.5
VIRTUAL INPUTS AND OUTPUTS
Sampled Value IEDs have additional virtual inputs and virtual outputs. These are mapped as new DDBs in the IED’s
PSL and are used as triggers for GOOSE messages to and from the IED. The GOOSE Control Blocks can be
configured using the IEC 61850 Configurator software tool, which is part of the Settings Application Software.
The additional inputs and outputs make it easier to apply the IEDs in full Digital Substations where switchgear
status, controls and commands are exchanged as GOOSE messages between the IEDs and Merging Units.
4.5.1
P446, P546, P841B VIRTUAL INPUTS AND OUTPUTS DDBS
Ordinal Signal Name Source Type Response
Description
1792 to 1823 GOOSEIN_33-64 Software GOOSEIN Protection Event
Virtual Input received from GOOSE message.
1888 to 1919 GOOSEOUT_33-64 PSL GOOSEOUT Protection Event
Virtual outputs. These allow you to control binary signals which can be mapped using the SCADA protocol output to other devices.
4.5.2 VIRTUAL CT AND VT RATIO SETTINGS
The Sampled Value frames are primary measurements. These come from Merging Units (MU) connected to
conventional CTs and VTs or Non-Conventional Instrument Transformers (NCITs). Alternatively they may come
directly from NCITs. The IED algorithms are typically based on secondary values. If primary values are needed, they
are calculated by the IED based on set CT or VT ratios.
The amplitudes for 1A CT inputs are limited to 64 A secondary. The amplitudes for 5A CT inputs are limited to 320 A
secondary. The VT secondary is limited to 200 V phase-to-earth. Therefore it is necessary to set appropriate CT and
VT ratios for the protection functions to operate correctly. The instrument transformer ratios are set in the IED
menu CT AND VT RATIOS, which is common to both conventional and Sampled Value IEDs.
Measurement from a Merging Unit connected to a CT
As this has a real CT ratio, set the real primary CT ratio.
Direct measurement from an NCIT
There is no physical CT ratio. Set the CT ratio high enough so the maximum primary current (maximum fault level)
when converted to secondary is not clamped.
P446SV Chapter 6 - Sampled Value Operation
P446SV-TM-EN-1 101