ABB Relion 670 Series Technical Reference Manual page 802

Section 13
Scheme communication
13.2
13.2.1
13.2.2
796
Phase segregated scheme communication logic for
distance protection ZC1PPSCH (85)
Function description
Phase segregated Scheme
communication logic for distance
protection
Introduction
Communication between line ends is used to achieve fault clearance for all faults on a
power line. All possible types of communication schemes for example, permissive
underreach, permissive overreach and blocking schemes are available. To manage
problems with simultaneous faults on parallel power lines phase segregated
communication is needed. This will then replace the standard Scheme communication
logic for distance or Overcurrent protection (ZCPSCH, 85) on important lines where
three communication channels (in each subsystem) are available for the distance
protection communication.
The main purpose of the Phase segregated scheme communication logic for distance
protection (ZC1PPSCH, 85) function is to supplement the distance protection function
such that:
• fast clearance of faults is also achieved at the line end for which the faults are on
the part of the line not covered by its underreaching zone.
• correct phase selection can be maintained to support single-pole tripping for faults
occurring anywhere on the entire length of a double circuit line.
To accomplish this, three separate communication channels, that is, one per phase,
each capable of transmitting a signal in each direction is required.
ZC1PPSCH (85) can be completed with the current reversal and WEI logic for phase
segregated communication, when found necessary in Blocking and Permissive
overreaching schemes.
Principle of operation
Depending on whether a reverse or forward directed impedance zone is used to issue
the send signal, the communication schemes are divided into Blocking and Permissive
schemes, respectively.
IEC 61850 IEC 60617
identification identification
ZC1PPSCH
1MRK505222-UUS C
ANSI/IEEE C37.2
device number
- 85
Technical reference manual