Sel SEL-487E-3 - Functional Overview; Protection Features

SEL-487E-3, -4 Data Sheet Schweitzer Engineering Laboratories, Inc.
4
Functional Overview
Protection Features
Differential Element
In the SEL-487E, the phase differential elements employ
operate (IOPn, where n = A, B, C) and restraint (IRTn)
quantities that the relay calculates from the selected wind-
ing input currents. Figure 2 shows the characteristic of
the filtered differential element as a straight line through
the origin of the form:
IOPA (IRTA) = SLPc • IRTA
For operating quantities (IOPA) exceeding the threshold
level O87P and falling in the operate region of Figure 2,
the filtered differential element issues an output. There
are two slope settings, namely Slope 1 (SLP1) and Slope 2
(SLP2). Slope 1 is effective during normal operating
conditions, and Slope 2 is effective when the fault detec-
tion logic detects an external fault condition. In general,
the relay uses filtered and unfiltered (instantaneous) ana-
log quantities in two separate algorithms to form the dif-
Figure 1 Functional Diagram
Available
Neutral
Input
Bus
3
3
1
1
3
3
3
3
3
SEL-487E
24
51N
50N
25
46
59
50BF
87T
51
4
EIA-232
2
Ethernet*
1
1
IRIG-B
REF
50BF
50BF
81
SEL-2800
ENV
49
BRM
DFR
HMI
LGC MET
PMU
SBMRTU SER TRM
85
RIO
SIP
HBL
68 79
32
27
67
87B
50
21
16
S
E
C
ANSI NUMBERS/ACRONYMS AND FUNCTIONS
16 SEC Access Security (Serial, Ethernet)
21* Phase and Ground Distance
24 Volts/Hertz
25 Synchronism Check
27 Undervoltage
32 Directional Power
46 Current Unbalance
49 IEEE C59.71 and IEC 60255-Compliant Thermal Model
50BF Dual Breaker Failure Overcurrent
50N Neutral Overcurrent
50
Overcurrent
(Phase, Zero-Sequence, and Negative-Sequence)
51N Neutral Time-Overcurrent
51
Time-Overcurrent
(Phase, Zero-Sequence, and Negative-Sequence)
59 Overvoltage
67
Directional Overcurrent
(Phase, Zero-Sequence, and Negative-Sequence)
68* Out-of-Step Block
79* Autoreclosing
81 Over- and Underfrequency
85 RIO SEL MIRRORED BITS Communications
87T
Transformer Differential
(Unrestrained, Restrained, Neg. Seq.)
87B* Bus Differential (Restrained)
ADDITIONAL FUNCTIONS
BRM Breaker Wear Monitor
DFR Event Reports
ENV SEL-2600 RTD Module*
HBL Harmonic Blocking
HMI Operator Interface
LDP Load Data Profiling
LGC SELOGIC Control Equations
MET High-Accuracy Metering
PMU Synchrophasors
REF Restricted Earth Fault
RTU Remote Terminal Unit
SER Sequential Events Recorder
SBM Station Battery Monitor
SIP Software-Invertible Polarities
TRM Transformer Monitor
1
Copper or Fiber Optic * Optional Feature
50
6751