CHAPTER 5: SETTINGS
CONTROL ELEMENTS
L90 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
5-391
5
Consider the selected protection element (or elements in combination) with the selection of
GND DIR O/C FWD
. For all the
forward external faults seen by an element used as
GND DIR O/C FWD
at one end of the line, the reverse-looking element
used as
GND DIR O/C REV
at the other end should picks up and provides a blocking signal. For greater security and to
overcome spurious directional element operation during transients, adding a pickup delay greater than the pilot channel
delay to the reverse directional element is recommended.
BLOCK SCHEME NO OF COMM BITS
— This setting specifies the number of bits of the communications channel available for
the scheme. With only one bit available, the scheme sends the blocking signal by asserting the
DIR BLOCK TX INIT
FlexLogic
operand. Use this operand to start the channel (set the blocking signal). On internal faults, the scheme removes the
blocking signal by asserting the
DIR BLOCK TX1
FlexLogic operand.
For tripping the scheme responds to lack of the blocking signal on bit 1 (
BLOCK SCHEME RX1
setting). The scheme uses only
local fault type identification provided by the phase selector to assert the output operands
DIR BLOCK TRIP A
,
B
,
C
, and
3P
.
To take advantage of the four-bit blocking scheme, initiate the blocking signals from a disturbance detector. This can be
accomplished by using both
50DD
and
DIR BLOCK TX INIT
to assert the blocking signal. Subsequently, specific bits are de-
asserted by the scheme based on the phase selection providing the peer relay with more information on the fault type.
Otherwise, the peer relay issues a three-pole trip upon receiving the bit pattern (0, 0, 0, 0).
BLOCK SCHEME RX1
through
BLOCK SCHEME RX4
— These settings allow the user to select the FlexLogic operands that
represent the receive signals for the scheme. Typically input contacts interfacing with a signaling system are used. In
single-bit applications,
BLOCK SCHEME RX1
must be used. In two-bit applications,
BLOCK SCHEME RX1
and
BLOCK SCHEME RX2
must be used. In four-bit applications,
BLOCK SCHEME RX1
,
BLOCK SCHEME RX2
,
BLOCK SCHEME RX3
, and
BLOCK SCHEME RX4
must be used.
Figure 5-221: Directional blocking scheme logic
Содержание L90
Страница 14: ...1 4 L90 LINE CURRENT DIFFERENTIAL SYSTEM INSTRUCTION MANUAL FOR FURTHER ASSISTANCE CHAPTER 1 INTRODUCTION 1 ...
Страница 68: ...2 54 L90 LINE CURRENT DIFFERENTIAL SYSTEM INSTRUCTION MANUAL SPECIFICATIONS CHAPTER 2 PRODUCT DESCRIPTION 2 ...
Страница 136: ...3 68 L90 LINE CURRENT DIFFERENTIAL SYSTEM INSTRUCTION MANUAL CONNECT TO D400 GATEWAY CHAPTER 3 INSTALLATION 3 ...
Страница 224: ...4 88 L90 LINE CURRENT DIFFERENTIAL SYSTEM INSTRUCTION MANUAL FLEXLOGIC DESIGN USING ENGINEER CHAPTER 4 INTERFACES 4 ...
Страница 692: ...6 36 L90 LINE CURRENT DIFFERENTIAL SYSTEM INSTRUCTION MANUAL PRODUCT INFORMATION CHAPTER 6 ACTUAL VALUES 6 ...
Страница 708: ...7 16 L90 LINE CURRENT DIFFERENTIAL SYSTEM INSTRUCTION MANUAL TARGETS MENU CHAPTER 7 COMMANDS AND TARGETS 7 ...
Страница 742: ...9 6 L90 LINE CURRENT DIFFERENTIAL SYSTEM INSTRUCTION MANUAL TESTING CHAPTER 9 COMMISSIONING 9 ...
Страница 804: ...10 62 L90 LINE CURRENT DIFFERENTIAL SYSTEM INSTRUCTION MANUAL FAULT LOCATOR CHAPTER 10 THEORY OF OPERATION 10 ...
Страница 872: ...C 6 L90 LINE CURRENT DIFFERENTIAL SYSTEM INSTRUCTION MANUAL COMMAND LINE INTERFACE APPENDIX C COMMAND LINE INTERFACE C ...
Страница 878: ...D 6 L90 LINE CURRENT DIFFERENTIAL SYSTEM INSTRUCTION MANUAL REVISION HISTORY APPENDIX D MISCELLANEOUS D ...
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