ABB 615 series Technical Manual page 635

1MAC059074-MB A
615 series ANSI
Technical Manual
voltage pickup value of 1.0 × Vn corresponds to 1.0 × 11.547 kV = 11.547 kV in the
primary.
Example 2: V0 is calculated from the phase quantities. The phase VT-ratio is 20/sqrt(3)
kV : 100/sqrt(3) V. In this case, "Calculated V0" is selected. The nominal value for
residual voltage is obtained from the VT ratios entered in Residual voltage V0:
Configuration/Analog inputs/Voltage (3V,VT): 20.000kV : 100V. The residual voltage
pickup value of 1.0 × Vn corresponds to 1.0 × 20.000 kV = 20.000 kV in the primary.
If "Calculated V0" is selected, the nominal value of residual voltage is
always phase-to-phase voltage. Thus, the valid maximum setting for
residual voltage Pickup value is 0.577 × Vn. The calculated V0 requires
that all three phase-to-ground voltages are connected to the protection
relay. V0 cannot be calculated from the phase-to-phase voltages.
Timer
Once activated, the timer activates the PICKUP output. The time characteristic is
according to DT. When the operation timer has reached the value set by Trip delay time,
the TRIP output is activated. If the fault disappears before the module trips, the reset timer
is activated. If the reset timer reaches the value set by Reset delay time, the operation timer
resets and the PICKUP output is deactivated.
The timer calculates the pickup duration value PICKUP_DUR, which indicates the
percentage ratio of the start situation and the set operation time. The value is available in
the monitored data view.
Blocking logic
There are three operation modes in the blocking function. The operation modes are
controlled by the BLOCK input and the global setting in Configuration/System/Blocking
mode which selects the blocking mode. The BLOCK input can be controlled by a binary
input, a horizontal communication input or an internal signal of the protection relay's
program. The influence of the BLOCK signal activation is preselected with the global
setting Blocking mode.
The Blocking mode setting has three blocking methods. In the "Freeze timers" mode, the
operation timer is frozen to the prevailing value, but the TRIP output is not deactivated
when blocking is activated. In the "Block all" mode, the whole function is blocked and the
timers are reset. In the "Block TRIP output" mode, the function operates normally but the
TRIP output is not activated.
Section 4
Protection functions
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