Virtual Inputs And Outputs; P446, P546, P841B Virtual Inputs And Outputs Ddbs; Virtual Ct And Vt Ratio Settings - GE MiCOM P40 Technical Manual

P446SV
DDB
Vsc1 Select x1
0
1
1
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
0
0
1
1
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
1792 to 1823 GOOSEIN_33-64
Virtual Input received from GOOSE message.
1888 to 1919 GOOSEOUT_33-64
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-TM-EN-1
DDB
Vsc1 Select 1x
1
0
1
DDB
Vsc2 Select 1x
0
1
0
1
Source Type
Description
Software GOOSEIN
PSL GOOSEOUT
Chapter 6 - Sampled Value Operation
Vsc1 Selection
Vcs2
Vcs3
Unused
Vsc2 Selection
Vcs2
Vcs3
Vcs1
Unused
Response
Protection Event
Protection Event
101