Overview
The “Negative sequence time overcurrent protection for machines” is intended primarily for the protection of generators against possible overheating of the rotor caused by negative sequence current in the stator current. NS2PTOC can also be used as a backup protection, that is, to protect the generator in case line protections or circuit breakers fail to clear unbalanced system faults.
For more detailed information on “Negative sequence time overcurrent protection for machines” 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 |
| Negative sequence time overcurrent protection for machines | NS2PTOC | 2I2 > | 46I2 |
Signals & Setting Parameters
NS2PTOC function block
NS2PTOC Input signals
| NS2PTOC Input signals | |||
| Name | Type | Default | Description |
| I3P | GROUP SIGNAL | – | Group connection for neg seq. |
| BLOCK | BOOLEAN | 0 | Block of function |
| BLKST1 | BOOLEAN | 0 | Block of step 1 |
| BLKST2 | BOOLEAN | 0 | Block of step 2 |
| BLKTR | BOOLEAN | 0 | Block of trip signals |
NS2PTOC Output signals
| NS2PTOC Output signals | |||
| Name | Type | Description | |
| TRIP | BOOLEAN | Common trip signal | |
| TR1 | BOOLEAN | Trip signal from step 1 | |
| TR2 | BOOLEAN | Trip signal from step 2 | |
| START | BOOLEAN | Common start signal | |
| ST1 | BOOLEAN | Start signal from step 1 | |
| ST2 | BOOLEAN | Start signal from step 2 | |
| ALARM | BOOLEAN | Alarm signal | |
| NSCURR | REAL | Negative sequence current in primary amps | |
NS2PTOC Non group settings (basic)
| NS2PTOC 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 |
NS2PTOC Group settings (basic)
| NS2PTOC Group settings (basic) | |||||
| Name | Values (Range) | Unit | Step | Default | Description |
| Operation | Off On |
– | – | Off | Operation Off / On |
| tAlarm | 0.00 – 6000.00 | s | 0.01 | 3.00 | Time delay for Alarm (operated by START signal), in sec |
| OpStep1 | Off On |
– | – | On | Enable execution of step 1 |
| I2-1> | 3 – 100 | %IB | 1 | 10 | Negative sequence current level for step 1 in % of IBase |
| CurveType1 | Definite Inverse |
– | – | Definite | Selection of definite or inverse time- characteri. for step 1 |
| t1 | 0.00 – 6000.00 | s | 0.01 | 10.00 | Definite time delay for trip of step 1, in sec |
| tResetDef1 | 0.000 – 60.000 | s | 0.001 | 0.000 | Time delay for reset of definite timer of step 1, in sec |
| K1 | 1.0 – 99.0 | s | 0.1 | 10.0 | Neg. seq. capability value of generator for step 1, in sec |
| t1Min | 0.000 – 60.000 | s | 0.001 | 5.000 | Minimum operate time for inverse curves for step 1 |
| t1Max | 0.00 – 6000.00 | s | 0.01 | 1000.00 | Maximum trip delay for step 1, in sec |
| ResetMultip1 | 0.01 – 20.00 | – | 0.01 | 1.00 | Reset multiplier for K1, defines reset time of inverse curve |
| OpStep2 | Off On |
– | – | On | Enable execution of step 2 |
| I2-2> | 3 – 100 | %IB | 1 | 10 | Negative sequence current level for step 2 in % of IBase |
| CurveType2 | Definite Inverse |
– | – | Definite | Selection of definite or inverse time- characteri. for step 2 |
| t2 | 0.00 – 6000.00 | s | 0.01 | 10.00 | Definite time delay for trip of step 2, in sec |
| tResetDef2 | 0.000 – 60.000 | s | 0.001 | 0.000 | Time delay for reset of definite timer of step 2, in sec |
| K2 | 1.0 – 99.0 | s | 0.1 | 10.0 | Neg. seq. capability value of generator for step 2, in sec |
| t2Min | 0.000 – 60.000 | s | 0.001 | 5.000 | Minimum operate time for inverse curves for step 2 |
| t2Max | 0.00 – 6000.00 | s | 0.01 | 1000.00 | Maximum trip delay for step 2, in sec |
| ResetMultip2 | 0.01 – 20.00 | – | 0.01 | 1.00 | Reset multiplier for K2, defines reset time of inverse curve |
NS2PTOC Monitored data
| NS2PTOC Monitored data | ||||
| Name | Type | Values (Range) | Unit | Description |
| NSCURR | REAL | – | A | Negative sequence current in primary amps |
Logics & highlights
Inverse time characteristic with t1Min and t1Max
Simplified logic diagram for step 1 of Negative sequence time overcurrent protection for machines (NS2PTOC)
Simplified logic diagram for the START, ALARM and TRIP signals for NS2PTOC
