Figure 389: Operating area of DQPTUV function
Quadrant II Generator produces active power, but draws reactive power (under-excited)
Quadrant III Generator produces both active and reactive power
The power direction can be reversed by setting
Pol reversal to “True”.
Timer
Once activated by both Under voltage detection and Reactive power monitoring
module, the Timer activates the
START
output. The Timer characteristic is according
to DT. When the operation timer has reached the value set by
Operate delay
time, the
OPERATE
output is activated. If the fault disappears before the module
operates, the Timer is reset instantaneously.
The Timer calculates the start duration value "START_DUR" which indicates the
percentage ratio of the start situation and the set operating time. The value is
available through 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 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. In the "Block all" mode,
the whole function is blocked and the timers are reset. In the "Block OPERATE
output" mode, the function operates normally but the
OPERATE
output is not
activated.
Protection functions
1MRS757644 H
746
620 series
Technical Manual
