Overview
The “Frequency time accumulation protection” for generator protection provides the START output for a particular settable frequency limit, when the system frequency falls in that settable frequency band limit and positive sequence voltage within settable voltage band limit. The START signal triggers the individual event timer, which is the continuous time spent within the given frequency band, and the accumulation timer, which is the cumulative time spent within the given frequency band.
For more detailed information on “Frequency time accumulation protection” function, refer to ABB, Relion 670 Series manuals.
To see other supported functions, click here.
Function Identification
| FTAQFVR Monitored data | ||||
| Name | Type | Values (Range) | Unit | Description |
| FREQ | REAL | – | Hz | Measured frequency value |
| ACCTIME | REAL | – | s | Accumulated time for frequency band limits |
Signals & Setting Parameters
FTAQFVR function block
FTAQFVR Input signals
| FTAQFVR Input signals | |||
| Name | Type | Default | Description |
| I3P | GROUP SIGNAL | – | Group signal for three phase current |
| U3P | GROUP SIGNAL | – | Group signal for three phase voltage |
| BLOCK | BOOLEAN | 0 | Block of function |
| CBCLOSE | BOOLEAN | 0 | Circuit breaker closed status input |
| CBOPEN | BOOLEAN | 0 | Circuit breaker open status input |
| LOADINIT | BOOLEAN | 0 | Loads the initial accumulation time to the function |
| HOLDACC | BOOLEAN | 0 | Holds the time accumulation when input is activated |
| RESETACC | BOOLEAN | 0 | Resetting the accumulated time of the function block |
FTAQFVR Output signals
| FTAQFVR Output signals | |||
| Name | Type | Description | |
| ERROR | BOOLEAN | Error output for incorrect settings | |
| TRIP | BOOLEAN | Trip signal of the function | |
| TRIPACC | BOOLEAN | Trip signal when accumulation time is exceeded the set limit | |
| TRIPCONT | BOOLEAN | Trip signal when continuous time is exceeded the set limit | |
| START | BOOLEAN | Start signal of the function | |
| ACCALARM | BOOLEAN | Alarm signal for reaching the frequency time accumulation value | |
| STRORHLD | BOOLEAN | Activated when function starts or HOLDACC input is active | |
| FREQOK | BOOLEAN | Indicates the system frequency within the frequency band limits | |
| VOLTOK | BOOLEAN | Indicates the system voltage within the voltage band limits | |
FTAQFVR Group settings (basic)
| FTAQFVR Group settings (basic) | |||||
| Name | Values (Range) | Unit | Step | Default | Description |
| Operation | Off On |
– | – | Off | Operation Off / On |
| tContinuous | 0.0 – 6000.0 | s | 0.1 | 20.0 | Continuous time limit for frequency band limits |
| tAccLimit | 10.0 – 90000.0 | s | 0.1 | 600.0 | Accumulation time limit for frequency band limits |
| FreqHighLimit | 35.00 – 90.00 | Hz | 0.01 | 47.50 | Frequency High limit value |
| FreqLowLimit | 30.00 – 85.00 | Hz | 0.01 | 47.00 | Frequency Low limit value |
| CBCheck | Disable Enable |
– | – | Enable | Enabling the generator start or stop detection logic |
| CurrStartLevel | 5.0 – 100.0 | %IB | 0.1 | 10.0 | Threshold current value of generator in percentage of base current |
| EnaVoltCheck | Disable Enable |
– | – | Enable | Enabling the voltage band limit check |
| UHighLimit | 0.0 – 200.0 | %UB | 1.0 | 200.0 | Voltage high limit for voltage band limit check |
| ULowLimit | 0.0 – 200.0 | %UB | 1.0 | 0.0 | Voltage low limit for voltage band limit check |
FTAQFVR Non group settings (basic)
| FTAQFVR 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 |
| initTimeAcc | 0.000 – 90000.000 | s | 0.001 | 0.0 | Initial accumulated time when LOADINIT command is executed |
FTAQFVR Monitored data
| FTAQFVR Monitored data | ||||
| Name | Type | Values (Range) | Unit | Description |
| FREQ | REAL | – | Hz | Measured frequency value |
| ACCTIME | REAL | – | s | Accumulated time for frequency band limits |
Logics & highlights
Typical stress magnification factor curve according ANSI/IEEE C37.106-2003 Standard
Examples of time frequency characteristics with various frequency band limits
Logical diagram
Technical data
