Sel SEL-411L User Manual

Schweitzer Engineering Laboratories, Inc. SEL-411L Data Sheet
Line Current Differential Protection
Automation and Control System
Key Features and Benefits
The SEL-411L Advanced Line Differential Protection, Automation, and Control System combines high-speed line cur-
rent differential, distance, and directional protection with complete bay control. This data sheet applies to all the model
options of the SEL-411L-0, -1, and -A relays. Table 5 details which features, functions, and applications are supported
by each of the SEL-411L models.
➤ Line Current Differential Protection. The 87L function of the SEL-411L provides protection for any transmission
line or cable with as many as three terminals over serial communications and as many as four terminals over
Ethernet communications, in three-pole or single-pole tripping modes. Each terminal can be connected in a dual
breaker arrangement.
➤ Generalized Alpha Plane. Phase-segregated (87LP), negative-sequence (87LQ), and zero-sequence (87LG)
differential elements use patented generalized alpha plane comparators. Combined with overcurrent supervision,
external fault detection, optional charging current compensation, and disturbance detection logic, these provide the
87L function with exceptional security and sensitivity. An adaptive feature increases security of the 87L function if:
➢ An external fault is detected
➢ Communications synchronization is degraded
➢ Charging current compensation is enabled but momentarily impossible because of loss-of-potential (LOP) or
other conditions
The generalized alpha plane principle is similar to the two-terminal SEL-311L. However, the SEL-311L and
SEL-411L are two completely independent hardware and firmware platforms. They are not compatible to be
applied in a line-current differential scheme.
➤ Inclusion of Power Transformers in the Protective Zone. The SEL-411L allows for in-line power transformer
applications by compensating for transformer vector group, ratio, and zero-sequence current. The 87L function
supports both harmonic blocking and/or harmonic restraint for stabilization during transformer inrush conditions.
During over-excitation conditions, the SEL-411L uses fifth-harmonic current to secure the 87L elements. The 87L
function can protect multiwinding transformers.
SEL-411L Advanced Line Differential
Protection, Automation, and Control System

Sel SEL-411L Specifications

General

Brand	Sel
Model	SEL-411L
Category	Control Systems
Language	English

Summary

Key Features and Benefits

Line Current Differential Protection

87L function provides protection for transmission lines or cables with up to three terminals.

Complete Distance Protection

Apply up to five zones of phase/ground distance and directional overcurrent elements.

High-Accuracy Traveling-Wave Fault Locator

Computes fault location using a double-ended traveling-wave algorithm for two-terminal lines.

Advanced Multiterminal Fault Locator

Efficiently dispatches crews to isolate line problems and restore service faster.

Functional Overview

Additional Functions

Lists additional functions supported by the SEL-411L relay, such as Access Security and Broken Conductor Detection.

Bay Control

Provides bay control functionality with status indication and control for disconnect switches.

Control Inputs and Outputs

Includes positions for up to three I/O boards with various optoisolated inputs and outputs.

Communications Features

Details communication features including Ethernet, serial, and protocols.

Metering and Monitoring

Access useful information with the metering function, including fundamental primary/secondary quantities.

Event Reporting and SER

Simplify post-fault analysis and improve understanding of protective scheme operations.

Protection Features

Complete Current Differential Protection

Compares phase, negative-sequence, and zero-sequence components from each line terminal.

Responses to System Conditions

Allows single-pole tripping and uses symmetrical components for fault identification.

Communications-Assisted Tripping Schemes

Supports schemes like POTT, DCUB, and DCB using MIRRORED BITS communications.

Broken Conductor Detection

Detects conductor breaks before they convert into shunt faults, mitigating hazards.

Multifunction Recloser With Flexible Applications

Includes single-pole and three-pole trip/reclose functions for one or two breakers.

Diagrams and Dimensions

4U Front Panel, Rack-Mount Option

Illustrates the front panel layout for the 4U rack-mount chassis.

5U Front Panel, Panel-Mount Option

Illustrates the front panel layout for the 5U panel-mount chassis.

7U Chassis Dimension

Illustrates the dimensions for the 7U chassis for rack and panel mounting.

Models and Options

Ethernet card options

Lists available Ethernet card port combinations for copper and fiber.

Communications protocols

Covers SEL protocols, Synchrophasors, DNP3, and IEC 61850 for communication.

SEL MIRRORED BITS Communications

Enables secure, bidirectional relay-to-relay digital communication.

Specifications

AC Current Inputs (Secondary Circuits)

Specifies current ratings, thermal ratings, and saturation current limits.

Differential Communications Ports

Specifies fiber optics communication port details for various wavelengths.

Electromagnetic (EMC) Immunity

Details EMC immunity standards and surge withstand capability.

Processing Specifications

Details AC voltage/current input processing and digital filtering.

Technical Support