Areva MiCOM P441, Техническое руководство

Страница: 286 / 636

P44x/EN AP/E33 Application Notes
Page 112/220 MiCOM P441/P442 & P444
4.2.2 The internal detection FUSE Failure condition
Is verified by follows (Fuse Failure not confirmed logic)
(Vr AND /I0 AND /l2 Et /I>) OR (FusFus_tri AND /Any_pole_dead AND V< AND /
∆Ι )
Vr>_FFUS : The residual voltage is bigger than a fixed threshold := 0,75Vn
I0>_FFUS : The zero sequence current is bigger than a settable threshold :
From 0.01 to 1.00 In by step of 0.01
I2>_FFUS : The negative sequence current is bigger than a settable threshold
identical to the I0 threshold.
I>_FFUS : The direct current is bigger than a fixed threshold equal to 2,5IN.
V<_FFUS : All the voltages are lower than a settable threshold from 0.05 à 1
Un by step of 0.1
∆Ι>
_FFUS : The line currents have a variation bigger than a settable value from
0.01 to 0.5 In by step of 0.01 In
FuseFailure_3P : Parameter in MiCOM S1 which allows the FFU tri pole detection
Any pole dead : Cycle in progress.
•
The I0 criteria (zero sequence current threshold) gives the possibility to UNBLOCK the
distance protection in case of phase to ground fault (if the fuse failure has not been yet
confirmed).
•
The I2 criteria (negative sequence current threshold) gives the possibility to
UNBLOCK the distance protection in case of insulated phase to phase fault (if the fuse
failure has not been yet confirmed).
•
The criteria (V< AND /
∆Ι)
gives the possibility to detect the 3Poles Fuse Failure(No
more phase voltage and no variation of current) (no specific logic about line
energisation).
4.2.3 Fuse Failure Alarm reset
In case of Fuse Failure confirmed, the condition which manages the Reset are given by :
Fusion_Fusible = 0
And
INP_FFUS_Line = 0
And
/All Pole Dead Or Healthy Network
•
All Pole Dead: No current AND no voltage OR CB Opened ((52a) if assigned in PSL)
U
N
. V
0
. I
0
. CVMR (convergence) . PSWING
•
Healthy Network:
Rated Line voltage AND
No V0 and No I0 AND
No start element AND
No Power Swing