Introduction; Rel356 Revision History - ABB REL 356 Instruction Booklet

Introduction

The REL 356 numerical current differential protection provides high speed protection for long and
short lines. It is particularly suitable for lines too short to be effectively protected by distance relays
and for tapped load applications. The current-only measuring principle offers advantages such as
insensitivity to power swings, mutuals and problems associated with ccvt's. Communication inter-
faces for 9600 bps audiotone or 64 kbps direct digital or fiber optic are available. The REL 356
protection system also provides digital fault recording, fault locating and extensive target records.
Features
· numerical processing
· proven sequence filter for current differential measurement
· trip time 18 – 26 msec typical for digital communication
· 64/56 kbps digital communication for optical fiber or multiplexers
· modem version for leased telephone lines, analog microwave or metallic pilot wires
· automatic channel delay measurement
· independent Direct Transfer Trip
· directional or non-directional high set phase and ground independent trip
· built-in optional distance back-up

REL356 Revision History

Main board
Version 1.21
Same as v 1.20 except an internal code modification due to new modem design.
Version 1.20
This version includes the following changes from v 1.15:
·
Added setting SOBT to allow longer reset time of the 52b contact.
·
Added setting for OPBR so that the selections are OPBR=IE/52B/BOTH/OUT.
·
Extended setting range for IPL and IGL
·
Improved 2
·
Metering display of IT (composite current), OP (operating value) and RES (restraint value)
·
OP and RES are now set in rms value instead of peak value
Version 1.15
Same as v 1.14 except a setting range change of TDES, trip-desensitizing feature.
Version 1.13
Same as v 1.12 except that distance back-up can be enabled.
Introduction & Revision History
(10/01/00)
(05/01/00)
nd harmonic filtering
(11/01/99)
(03/29/99)
ABB REL 356 Current Differential Protection
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