Scheme Communication Logic For Residual Overcurrent Protection Ecpsch; Identification; Functionality - ABB RED650 Technical Manual

1MRK 505 394-UEN A
13.4
13.4.1
13.4.2
Line differential protection RED650 2.2 IEC
Technical manual
currents have been above the set value MinCurr for more than setting tLowCurr, an
overreaching zone will be allowed to trip "instantaneously" during a fault condition
when one or two of the phase currents will become low due to a three-phase trip at
the opposite IED, see figure 206. The current measurement is performed internally
and the internal STILL signal becomes logical one under the described conditions.
The load current in a healthy phase is in this way used to indicate the tripping at the
opposite IED. Note that this function will not operate in case of three-phase faults,
because none of the phase currents will be low when the opposite IED is tripped.
IEC05000158 V1 EN-US
Figure 206: Loss-of-load acceleration - simplified logic diagram
Breaker closing signals can if decided be connected to block the function during
normal closing.
Scheme communication logic for residual
overcurrent protection ECPSCH

Identification

Function description
Scheme communication logic for
residual overcurrent protection

Functionality

To achieve fast fault clearance of earth faults on the part of the line not covered by
the instantaneous step of the residual overcurrent protection, the directional
residual overcurrent protection can be supported with a logic that uses
communication channels.
In the directional scheme, information of the fault current direction must be
transmitted to the other line end. With directional comparison, a short operate time
Scheme communication
IEC 61850 IEC 60617
identification identification
ECPSCH -
Section 13
M13819-14 v2
IP14711-1 v2
M14882-1 v2
ANSI/IEEE C37.2
device number
85
M13918-4 v11
417