Overview
The “Additional security logic for differential protection (LDRGFC)” can help the security of the protection especially when the communication system is in abnormal status or for example when there is unspecified asymmetry in the communication link. It helps to reduce the probability for mal-operation of the protection.
For more detailed information on “Additional security logic for differential protection (LDRGFC)”, refer to ABB, Relion 670 Series manuals.
To see other supported functions, click here.
Function Identification
| Function description | IEC 61850 identification |
IEC 60617 identification |
ANSI/IEEE C37.2 device number |
| Additional security logic for differential protection | LDRGFC | – | 11 |
Signals & Setting Parameters
LDRGFC Function block
LDRGFC Input signals
| LDRGFC Input signals | |||
| Name | Type | Default | Description |
| I3P | GROUP SIGNAL | – | Group signal for current input |
| U3P | GROUP SIGNAL | – | Group signal for voltage input |
| BLOCK | BOOLEAN | 0 | Block of function |
| BLKCV | BOOLEAN | 0 | Block of ph to ph current variation criterion |
| BLKUC | BOOLEAN | 0 | Block of the low current criterion |
| BLK3I0 | BOOLEAN | 0 | Block of zero sequence current criterion |
| BLKUV | BOOLEAN | 0 | Block of under voltage criterion |
| REMSTUP | BOOLEAN | 0 | Startup signal of remote end |
LDRGFC Output signals
| LDRGFC Output signals | |||
| Name | Type | Description | |
| START | BOOLEAN | General startup signal | |
| STCVL1L2 | BOOLEAN | Start signal for current variation criterion for phase L1L2 | |
| STCVL2L3 | BOOLEAN | Start signal for current variation criterion for phase L2L3 | |
| STCVL3L1 | BOOLEAN | Start signal for current variation criterion for phase L3L1 | |
| STUC | BOOLEAN | Start signal for low current criterion | |
| ST3I0 | BOOLEAN | Start signal for zero sequence current criterion | |
| STUV | BOOLEAN | Start signal for under voltage criterion | |
LDRGFC Group settings (basic)
| LDRGFC Group settings (basic) | |||||
| Name | Values (Range) | Unit | Step | Default | Description |
| Operation | Off On |
– | – | Off | Operation Off/On |
| tStUpReset | 0.000 – 60.000 | s | 0.001 | 7.000 | Reset delay for startup signal |
| OperationCV | Off On |
– | – | On | Operation current variation Off/On |
| ICV> | 1 – 100 | %IB | 1 | 20 | Fixed threshold for ph to ph current variation criterion |
| OperationUC | Off On |
– | – | On | Operation low current criterion Off/On |
| IUC< | 1 – 100 | %IB | 1 | 5 | Start value for low current operation in % of IBase |
| Operation3I0 | Off On |
– | – | On | Operation zero sequence current criterion Off/On |
| I3I0> | 1 – 100 | %IB | 1 | 10 | Start value for zero sequence current criterion in % of IBase |
| OperationUV | Off On |
– | – | On | Operation under voltage criterion Off/On |
| UPhN< | 1 – 100 | %UB | 1 | 60 | Start value for phase voltage criterion in % of UBase |
| UPhPh< | 1 – 100 | %UB | 1 | 60 | Start value for ph to ph voltage criterion in % of UBase |
LDRGFC Group settings (advanced)
| LDRGFC Group settings (advanced) | |||||
| Name | Values (Range) | Unit | Step | Default | Description |
| tCV | 0.000 – 0.005 | s | 0.001 | 0.002 | Time delay for phase to phase current variation |
| tUC | 0.000 – 60.000 | s | 0.001 | 0.200 | Time delay for low current criterion |
| t3I0 | 0.000 – 60.000 | s | 0.001 | 0.000 | Time delay for zero sequence current criterion |
| tUV | 0.000 – 60.000 | s | 0.001 | 0.000 | Time delay for low voltage criterion |
LDRGFC Non group settings (basic)
| LDRGFC Non group settings (basic) | |||||
| Name | Values (Range) | Unit | Step | Default | Description |
| GlobalBaseSel | 1 – 12 | – | 1 | 1 | Selection of one of the Global Base Value groups |
LDRGFC Monitored data
| LDRGFC Monitored data | ||||
| Name | Type | Values (Range) | Unit | Description |
| IL1 | REAL | – | A | Current RMS value for phase L1 |
| IL2 | REAL | – | A | Current RMS value for phase L2 |
| IL3 | REAL | – | A | Current RMS value for phase L3 |
| 3I0 | REAL | – | A | Zero sequence current value |
| UL1 | REAL | – | kV | Voltage RMS value for phase L1 |
| UL2 | REAL | – | kV | Voltage RMS value for phase L2 |
| UL3 | REAL | – | kV | Voltage RMS value for phase L3 |
| UL12 | REAL | – | kV | Voltage RMS value for ph to ph L1L2 |
| UL23 | REAL | – | kV | Voltage RMS value for ph to ph L2L3 |
| UL31 | REAL | – | kV | Voltage RMS value for ph to ph L3L1 |
Logics & highlights
LDRGFC Current variation logic diagram
LDRGFC Zero sequence current criterion logic diagram
LDRGFC Low voltage criterion logic diagram
LDRGFC Low current criterion logic diagram
LDRGFC Logic diagram for start up element
