SEL-411L

Advanced Line Differential Protection, Automation, and Control System

The SEL-411L is a high-performance line differential protection, automation, and control system. It integrates high-speed line current differential, distance, and directional protection with complete bay control capabilities. It can protect up to four terminals via Ethernet or three terminals via serial communications and supports modern digital secondary system technologies like TiDL and SV for substation modernization.

Key Features

Line Current Differential Protection (87L)

Uses patented Generalized Alpha Plane technology to ensure stability against external faults and communication errors while providing high-speed subcycle protection.
Distance Protection

Features five zones of Mho and Quadrilateral elements for phase and ground distance, with enhanced security through CCVT transient overreach logic.
High-Accuracy Fault Locating

Utilizes traveling-wave technology to pinpoint faults within one tower span, significantly reducing transmission line restoration time.
Broken Conductor Detection

Detects open-phase conditions on overhead lines to issue alarms or trip breakers before they escalate into ground faults, preventing fires or personal injury.
Digital Process Bus Support

Implements SEL TiDL and SV technologies to replace copper cabling with fiber optics, improving safety and reducing costs.
In-Line Transformer Compensation

Compensates for connection type, ratio, and zero-sequence current of power transformers within the line, allowing for integrated line and transformer protection.
Bay Control and Reclosing

Provides control for up to two breakers and monitoring for three, with integrated support for single-pole and three-pole reclosing.
Synchrophasors

Provides real-time system state measurement data according to the IEEE C37.118 standard for wide-area monitoring and control.

Customizable Front Panel

Features a large LCD, 24 programmable target LEDs, and 12 user-configurable buttons for intuitive local control and status monitoring.
One-Line Mimic Display

Displays the system configuration in a one-line diagram format on the front LCD, showing real-time status of breakers and disconnects.
Built-in Web Server

Allows easy access to relay status, settings, metering values, and event records via a web browser over a standard Ethernet network.
Powerful Configuration Software

Uses ACSELERATOR QuickSet and Grid Configurator for rapid creation, management, and deployment of settings, featuring graphical logic editing.
Multiple Communication Protocols

Supports various industry-standard protocols, including IEC 61850, DNP3, PRP, HSR, and PTP, ensuring easy integration with existing systems.
Advanced Monitoring

Includes breaker contact wear monitoring, station battery monitoring, and thermal overload protection to enhance maintenance efficiency.
Flexible Mounting Options

Offers vertical or horizontal mounting and panel or rack-mount chassis options, with I/O board expansion to meet diverse input/output requirements.