Areva MiCOM P441, Technical Manual

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Application Notes P44x/EN AP/E33
MiCOM P441/P442 & P444 Page 67/220
All Pole Dead
The DDB All Pole Dead if assigned in PSL, indicates all pole are dead (All 3 poles are
opened)
SOTF/TOR Trip
The DDB SOTF/TOR Trip if assigned in PSL, indicates a 3poles trip by TOR or SOTF logic -
see Figure 37
2.13 Power swing blocking (PSB)
Power swings are oscillations in power flow which can follow a power system disturbance.
They can be caused by sudden removal of faults, loss of synchronism across a power
system or changes in direction of power flow as a result of switching. Such disturbances can
cause generators on the system to accelerate or decelerate to adapt to new power flow
conditions, which in turn leads to power swinging. A power swing may cause the impedance
presented to a distance relay to move away from the normal load area and into one or more
of its tripping characteristics. In the case of a stable power swing it is important that the relay
should not trip. The relay should also not trip during loss of stability since there may be a
utility strategy for controlled system break up during such an event.
Menu text Default setting Setting range Step size
Min Max
GROUP 1
POWER SWING
Delta R
0.5/In
Ω
0
400/In
Ω
0.01/In
Ω
Delta X
0.5/In
Ω
0
400/In
Ω
0.01/In
Ω
IN > Status Enabled Disabled or Enabled
IN > (% Imax) 40% 10% 100% 1%
I2 > Status Enabled Disabled or Enabled
I2 > (% Imax) 30% 10% 100% 1%
Imax line > Status Enabled Disabled or Enabled
Imax line > 3 x In 1 x In 20 x In 0.01 x In
Unblocking Time delay 30s 0 30s 0.1s
Blocking Zones 00000000 Bit 0: Z1/Z1X Block, Bit 1: Z2 Block,
Bit 2: Z3 Block, Bit 3: Zp Block.