![Sel SEL-421 User Manual Download Page 41](http://html1.mh-extra.com/html/sel/sel-421/sel-421_user-manual_1236405041.webp)
xliii
Date Code 20020501
SEL-421/SEL-421-1 Relay
Preface
lists the current firmware versions and
details differences between the current and previous versions.
Applications
Handbook
Section 1: Protection Application Examples
.
provides the following
protection schemes with explanations and settings:
➤
Overhead single 230 kV transmission line
➤
Overhead parallel 500 kV transmission lines with zero-
sequence mutual coupling
➤
Overhead tapped 345 kV transmission line
➤
Parallel submarine 230 kV underground cables
This section also provides separate application examples for out-of-
step blocking and tripping, circuit breaker failure protection, and
automatic reclose and synchronism checking.
Section 2: Monitoring and Metering
.
describes how to use the circuit
breaker monitors and the substation dc battery monitors; provides
information on viewing fundamental and rms metering quantities for
voltages and currents, as well as power and energy metering data.
explains how to obtain and interpret high-
resolution raw data oscillograms, filtered event reports, event
summaries, history reports, and SER reports; discusses how to enter
SER trigger and alias settings.
Section 4: Time-Synchronized Measurements
.
explains synchronized
phasor measurements and estimation of power system states using the
SEL-421 Relay high-accuracy time-stamping capability; presents real-
time load flow/power flow application ideas.
Section 5: Substation Automatic Restoration
describes an example of
automatic substation restoration; gives a real-world example of the
programming ease and flexibility of free-form expanded SEL
OGIC®
control equations.
Section 6: SEL-2030 Applications
provides examples of how to use the
SEL-421 Relay with the SEL-2020 and SEL-2030 Communications
Processors for total substation automation solutions.
Section 7: Direct Network Communication
.
explains how to use DNP 3.0
and the Ethernet protocols such as Telnet, FTP, and UCA2.
Reference Manual
Section 1: Protection Functions
describes the function of various relay
protection elements; describes how the relay processes these elements;
gives detailed specifics on protection scheme logic for POTT, DCB,
DCUB, and DTT; provides trip logic diagrams, and current and
voltage source selection details.
Section 2: Auto-Reclose and Synchronism Check
explains how to operate
the SEL-421 Relay two-circuit breaker multi-shot recloser; describes
how to set the SEL-421 Relay for single-pole reclosing, three-pole
reclosing, or both; shows selection of the lead and follow circuit
breakers; explains how to set and apply synchronism-check elements
for automatic and manual closing.
describes SEL
OGIC
control equations and how to apply these equations; discusses
expanded SEL
OGIC
control equation features such as PLC-style
commands, math functions, counters, and conditioning timers;
provides a tutorial for converting older format SEL
OGIC
control
equations to new free-form equations.
Summary of Contents for SEL-421
Page 8: ...This page intentionally left blank ...
Page 30: ...This page intentionally left blank ...
Page 110: ...This page intentionally left blank ...
Page 204: ...This page intentionally left blank ...
Page 284: ...This page intentionally left blank ...