SEL-487E

Transformer Protection Relay

The SEL-487E is a high-speed transformer differential relay that supports up to six terminals (windings). Beyond basic transformer protection, this device offers powerful performance capable of simultaneously protecting transformers, buses, lines, and feeders within a single unit. Notably, it supports SEL’s Digital Secondary System (DSS) technologies, such as TiDL and Sampled Values (SV), making it a core device for implementing Centralized Protection and Control (CPC) functions in modern digital substations.

Key Features

Six-Terminal Differential Protection (87)

Supports current inputs for up to six terminals, providing complete protection for complex multi-winding transformers or configurations involving multiple breakers.
Integrated Protection Scheme

Includes not only differential protection but also distance (21), directional overcurrent (67), and time-overcurrent (51) elements, allowing the integration of primary and backup protection for various substation equipment into a single device.
Three Restricted Earth Fault (REF) Elements

Provides three independent REF elements to detect sensitive internal and external ground faults with greater precision.
High-Speed Sampling and Processing

Utilizes high-speed sampling at 8,000 samples per second to rapidly detect faults and minimize transformer damage.
Digital Substation Solution Support

TiDL Technology: Performs data transmission and protection via point-to-point fiber-optic connections.
IEC 61850-9-2 Sampled Values (SV): Transmits and receives digital data based on international standard protocols, drastically reducing wiring complexity.
Advanced Thermal Modeling

Precisely manages transformer overload conditions using thermal models compliant with IEEE C57.91 and IEC 60255 standards.

Comprehensive Asset Management

Through-Fault Monitor: Records accumulated stress on the transformer to predict lifespan and manage maintenance cycles.
Breaker Status Monitoring: Monitors breaker contact wear and operational status to support preventative maintenance.
Latest Communication Redundancy Protocols

Supports PRP (Parallel Redundancy Protocol) and HSR (High-Availability Seamless Redundancy) to maintain stable protection without data loss even during network failures.
Flexible Communication Port Configuration

Provides multiple Ethernet ports, including SFP optical ports, as well as serial ports to adapt to various network environments.
Precision Time Synchronization

Provides microsecond-level timing via PTPv2 (IEEE 1588) and IRIG-B inputs, ensuring accurate time-series data for disturbance analysis.
Engineering Simplification

Reduces the number of devices and wiring within the substation by consolidating multiple protection functions, thereby lowering design and maintenance costs.
SEL Grid Configurator Support

Enables quick and easy configuration of complex settings and logic through intuitive software.