Overview
The “100% stator earth fault protection” is used to detect earth faults in the stator windings of generators and motors. STTIPHIZ is applicable for generators connected to the power system through a unit transformer in a block connection.
For more detailed information on “100% stator earth fault protection, injection based” function, 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 |
| 100% stator earth fault protection, injection based | STTIPHIZ | Res < | 64S |
Signals & Setting Parameters
STTIPHIZ function block
STTIPHIZ Input signals
| STTIPHIZ Input signals | |||
| Name | Type | Default | Description |
| USU | GROUP SIGNAL | – | Injected voltage signal |
| USI | GROUP SIGNAL | – | Injected current signal (voltage over shunt) |
| BLOCK | BOOLEAN | 0 | Block of function |
| ZREFSEL | INTEGER | 1 | Reference impedance selection |
STTIPHIZ Output signals
| STTIPHIZ Output signals | |||
| Name | Type | Description | |
| TRIP | BOOLEAN | Trip | |
| START | BOOLEAN | Start | |
| ALARM | BOOLEAN | Alarm | |
| OPCIRC | BOOLEAN | Injection circuit open | |
| ERROR | BOOLEAN | Error | |
| ERRSTAT | INTEGER | Error indication | |
| RAVE | REAL | Measured resistance to earth in Ohm at inj freq | |
| XAVE | REAL | Measured reactance to earth in Ohm at inj freq | |
| FREQU | REAL | Measured frequency of injected voltage into stator | |
| RFAULT | REAL | Estimated fault resistance in Ohm | |
| ZREF | INTEGER | Selected reference impedance number | |
| ZREFRE | REAL | Used reference impedance real part in Ohm | |
| ZREFIM | REAL | Used reference impedance imaginary part in Ohm | |
| URMSSTAT | BOOLEAN | RMS voltage status, TRUE when > ULimRMS | |
STTIPHIZ Group settings (basic)
| STTIPHIZ Group settings (basic) | |||||
| Name | Values (Range) | Unit | Step | Default | Description |
| Operation | Off On |
– | – | Off | Operation On / Off |
| RTrip | 100 – 10000 | Ohm | 1 | 1000 | Trip limit of fault resistance in Ohm |
| RAlarm | 100 – 100000 | Ohm | 1 | 5000 | Alarm limit of fault resistance in Ohm |
| tAlarm | 0.00 – 600.00 | s | 1.00 | 30.00 | Alarm time delay |
| OpenCircLim | 100 – 10000000 | Ohm | 1 | 10000000 | Open circuit limit in Ohm |
| ULimRMS | 1 – 1000 | V | 1 | 100 | RMS voltage level |
STTIPHIZ Group settings (advanced)
| STTIPHIZ Group settings (advanced) | |||||
| Name | Values (Range) | Unit | Step | Default | Description |
| FreqInjected | 50.000 – 250.000 | Hz | 0.001 | 87.000 | Injected frequency |
STTIPHIZ Non group settings (basic)
| STTIPHIZ Non group settings (basic) | |||||
| Name | Values (Range) | Unit | Step | Default | Description |
| k1Real | -10000000000.00 0 – 10000000000.00 0 |
– | 0.001 | 10000.000 | Multiplication factor k1 for calibration, real part |
| k1Imag | -10000000000.00 0 – 10000000000.00 0 |
– | 0.001 | 0.000 | Multiplication factor k1 for calibration, imaginary part |
| k2Real | -10000000000.00 0 – 10000000000.00 0 |
Ohm | 0.001 | 0.000 | Addition factor k2 for calibration, real part in Ohm |
| k2Imag | -10000000000.00 0 – 10000000000.00 0 |
Ohm | 0.001 | 0.000 | Addition factor k2 for calibration, imaginary part in Ohm |
| RefR1 | 0.001 – 1000000000.000 | Ohm | 0.001 | 1000.000 | Reference resistance R1 in ohm |
| RefX1 | -1000000.000 – 1000000.000 |
Ohm | 0.001 | 2000.000 | Reference reactance X1 in ohm |
| RefR2 | 0.001 – 1000000000.000 | Ohm | 0.001 | 1000.000 | Reference resistance R2 in ohm |
| RefX2 | -1000000.000 – 1000000.000 |
Ohm | 0.001 | 2000.000 | Reference reactance X2 in ohm |
| RefR3 | 0.001 – 1000000000.000 | Ohm | 0.001 | 1000.000 | Reference resistance R3 in ohm |
| RefX3 | -1000000.000 – 1000000.000 |
Ohm | 0.001 | 2000.000 | Reference reactance X3 in ohm |
| RefR4 | 0.001 – 1000000000.000 | Ohm | 0.001 | 1000.000 | Reference resistance R4 in ohm |
| RefX4 | -1000000.000 – 1000000.000 |
Ohm | 0.001 | 2000.000 | Reference reactance X4 in ohm |
| RefR5 | 0.001 – 1000000000.000 | Ohm | 0.001 | 1000.000 | Reference resistance R5 in ohm |
| RefX5 | -1000000.000 – 1000000.000 |
Ohm | 0.001 | 2000.000 | Reference reactance X5 in ohm |
STTIPHIZ Non group settings (advanced)
| STTIPHIZ Non group settings (advanced) | |||||
| Name | Values (Range) | Unit | Step | Default | Description |
| FilterLength | 1 s 2 s |
– | – | 1 s | Length of filter buffer |
STTIPHIZ Monitored data
| STTIPHIZ Monitored data | ||||
| Name | Type | Values (Range) | Unit | Description |
| RAVE | REAL | – | Ohm | Measured resistance to earth in Ohm at inj freq |
| XAVE | REAL | – | Ohm | Measured reactance to earth in Ohm at inj freq |
| FREQU | REAL | – | Hz | Measured frequency of injected voltage into stator |
| RFAULT | REAL | – | Ohm | Estimated fault resistance in Ohm |
| ZREF | INTEGER | – | – | Selected reference impedance number |
| ZREFRE | REAL | – | Ohm | Used reference impedance real part in Ohm |
| ZREFIM | REAL | – | Ohm | Used reference impedance imaginary part in Ohm |
| URMSSTAT | BOOLEAN | – | – | RMS voltage status, TRUE when > ULimRMS |
Logics & highlights
Definition of errors
Logic for maximum displayed value by RFAULT
Example installation for stator injection
Injection unit REX060
Generator earthing alternatives
A: High-resistance earthing with a neutral point resistor
B: Effective high-resistance earthing via a distribution transformer
High-resistance generator earthing with a neutral point resistor resistor (IEC earthing) and injection through SIT at neutral point
Effective high-resistance generator earthing via a distribution transformer (ANSI grounding) and injection through a SIT at neutral point
Equivalent of the impedance measurement
Open circuit characteristics
Reference impedance
Admittance
Trip time characteristic as function of fault resistance
Simplified logic diagram for 100% stator earth fault protection STTIPHIZ
STTIPHIZ alarm and trip logic
