Schweitzer Engineering SEL-351P, Quick Start Manual

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Date Code 990430 Setting SEL
OGIC
®
Control Equations G-1
SEL-351P Manual Técnico
APPENDIX G: SETTING SEL
OGIC
®
CONTROL EQUATIONS
SEL
OGIC
®
Control Equations combine relay protection and control elements with logic operators
to create custom protection and control schemes. This appendix shows how to set the protection
and control elements (Relay Word bits) in the SEL
OGIC
Control Equations.
Additional SEL
OGIC
Control Equation setting details are available in Section 9: Setting the
SEL-351P Recloser Control (see also Settings Sheets 13 through 17 in the back of Section 9 ).
See the SHO command (Show/View Settings) in Section 10: Serial Port Communications and
Commands for a list of the factory settings shipped with the SEL - 351P Recloser Control in a
standard relay shipment.
R
ELAY
W
ORD
B
ITS
Most of the protection and control element logic outputs shown in the various figures in
Section 3: Overcurrent, Voltage, Synchronism Check, and Frequency Elements through
Section 8: Breaker/Recloser Monitor, Battery System Monitor, Metering, and Load Profile
Functions
are Relay Word bits (labeled as such in the figures). Each Relay Word bit has a label
name and can be in either of the following states:
1 (logical 1) or 0 (logical 0)
Logical 1 represents an element being picked up, timed out, or otherwise asserted.
Logical 0 represents an element being dropped out or otherwise deasserted.
A complete listing of Relay Word bits and their descriptions are referenced in Table 9.3 in
Section 9: Setting the SEL-351P Recloser Control .
Relay Word Bit Operation Example – Phase Time-Overcurrent Element 51P1T
As an example of protection element operation via the logic output of Relay Word bits, a phase
time-overcurrent element is examined. Refer to phase time-overcurrent element 51PIT in
Figure 3.14 in
Section 3: Overcurrent, Voltage, Synchronism Check, and Frequency
Elements . Read the text that accompanies Figure 3.14 (Table 3.3 and following text). The
following Relay Word bits are the logic outputs of the phase time-overcurrent element:
51P1 indication that the maximum phase current magnitude is above the level of the
phase time-overcurrent pickup setting 51P1P
51P1T indication that the phase time-overcurrent element has timed out on its curve
51P1R indication that the phase time-overcurrent element is fully reset
Phase Time-Overcurrent Element 51P1T Pickup Indication
If the maximum phase current is at or below the level of the phase time-overcurrent pickup
setting 51P1P, Relay Word bit 51P is in the following state:
51P1 = 0 (logical 0)