ABB RES670 Technical Manual page 246

Section 8
Current protection
240
Trip from this function can be blocked from the binary input BLKTRDIR.
When the function picks up, binary output signals PICKUP and PUDIRIN are
activated. If the output signals PICKUP and PUDIRIN remain active for the set delay
tDef the binary output signals TRIP and TRDIRIN get activated.
The function indicates forward/reverse direction to the fault. Reverse direction is
defined as φ is within the angle sector: RCADir + 180° ± ROADir
This variant has definite time delay.
Directional functions
For all the directional functions there are directional pickup signals PUFW: fault in the
forward direction, and PUREV: fault in the reverse direction. Even if the directional
function is set to operate for faults in the forward direction, a fault in the reverse
direction will give the pickup signal PUREV. Also if the directional function is set to
operate for faults in the reverse direction, a fault in the forward direction will give the
pickup signal PUFW.
Non-directional ground fault current protection
This function will measure the residual current without checking the phase angle. The
function will be used to detect cross-country faults. This function can serve as
alternative or backup to distance protection with phase preference logic. To assure
selectivity the distance protection can block the non-directional ground fault current
function via the input BLKNDN.
The non-directional function is using the calculated residual current, derived as sum of
the phase currents. This will give a better ability to detect cross-country faults with
high residual current, also when dedicated core balance CT for the sensitive ground
fault protection will saturate.
This variant has the possibility of choice between definite time delay and inverse time
delay (TimeChar parameter). The inverse time delay shall be according to IEC
60255-3.
For trip, the residual current 3I
Trip from this function can be blocked from the binary input BLKNDN.
When the function picks up, binary output signal PUNDIN is activated. If the output
signal PUNDIN remains active for the set delay tINNonDir or after the inverse time
delay the binary output signals TRIP and TRNDIN get activated.
Residual overvoltage release and protection
All the directional functions shall be released when the residual voltage gets higher
than a set level VNRelPU.
shall be larger than the set level (INNonDirPU).
0
Phasor measurement unit RES670 2.2 ANSI
1MRK 511 408-UUS A
SEMOD171963-60 v4
SEMOD171963-63 v6
SEMOD171963-72 v8
Technical manual