Overview
The “Mho impedance supervision logic (ZSMGAPC)” includes features for fault inception detection and high SIR detection. It also includes the functionality for loss of potential logic as well as for the pilot channel blocking scheme. ZSMGAPC can mainly be decomposed in two different parts: A fault inception detection logic, and High SIR detection logic.
For more detailed information on “Mho impedance supervision logic (ZSMGAPC)”, refer to ABB, Relion 670 Series manuals.
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Function Identification
| Function description | IEC 61850 identification |
IEC 60617 identification |
ANSI/IEEE C37.2 device number |
| Mho Impedance supervision logic | ZSMGAPC | – | – |
Signals & Setting Parameters
ZSMGAPC function block
ZSMGAPC Input signals
| ZSMGAPC Input signals | |||
| Name | Type | Default | Description |
| I3P | GROUP SIGNAL | – | Three phase current samples and DFT magnitude |
| U3P | GROUP SIGNAL | – | Three phase phase-neutral voltage samples and DFT magnitude |
| BLOCK | BOOLEAN | 0 | Block of the function |
| REVSTART | BOOLEAN | 0 | Indication of reverse start |
| BLOCKCS | BOOLEAN | 0 | Blocks the blocking carrier signal to remote end |
| CBOPEN | BOOLEAN | 0 | Indicates that the breaker is open |
ZSMGAPC Output signals
| ZSMGAPC Output signals | |||
| Name | Type | Description | |
| BLKZMTD | BOOLEAN | Block signal for blocking of time domained mho | |
| BLKCHST | BOOLEAN | Blocking signal to remote end to block overreaching zone | |
| CHSTOP | BOOLEAN | Stops the blocking signal to remote end | |
| HSIR | BOOLEAN | Indication of source impedance ratio above set limit | |
ZSMGAPC Group settings (basic)
| ZSMGAPC Group settings (basic) | |||||
| Name | Values (Range) | Unit | Step | Default | Description |
| PilotMode | Off On |
– | – | Off | Pilot mode Off/On |
| Zreach | 0.1 – 3000.0 | Ohm | 0.1 | 38.0 | Line impedance |
| IMinOp | 10 – 30 | %IB | 1 | 20 | Minimum operating current for SIR measurement |
ZSMGAPC Group settings (advanced)
| ZSMGAPC Group settings (advanced) | |||||
| Name | Values (Range) | Unit | Step | Default | Description |
| DeltaI | 0 – 200 | %IB | 1 | 10 | Current change level in % of IBase for fault inception detection |
| Delta3I0 | 0 – 200 | %IB | 1 | 10 | Zero seq current change level in % of IBase |
| DeltaU | 0 – 100 | %UB | 1 | 5 | Voltage change level in % of UBase for fault inception detection |
| Delta3U0 | 0 – 100 | %UB | 1 | 5 | Zero seq voltage change level in % of UBase |
| SIRLevel | 5 – 15 | – | 1 | 10 | Settable level for source impedance ratio |
ZSMGAPC Non group settings (basic)
| ZSMGAPC 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 |