Project Description

SEL-451 Protection, Automation, and Bay Control System

SEL-451 Protection, Automation, and Bay Control System

The new SEL-451 is a complete stand-alone protection, automation, and control system. The SEL-451 has speed, power, and flexibility to combine complete substation bay control with high-speed breaker protection in one economical system. Use the SEL-451 as an integral part of a full substation protection, control, and monitoring solution. Reduce Maintenance costs by accurately tracking breaker operation. Monitor breaker interruption times and accumulated breaker duty to easily determine the need for proactive maintenance. Integrate information with SCADA or automation systems though a communications processor or directly to the Ethernet port.

Functional Overview

SEL-451 Functional Overview
16SEC Access Security
21 Phase and Ground Distance
25 Synchronism Check
27 Undervoltage
50 Instantaneous Overcurrent
50BF Dual Circuit Breaker Failure
50G Best Choice Ground
51 Time-Overcurrent
52PB Trip/Close Pushbuttons
59 Overvoltage
59 (P,G,Q) Overvoltage (Phase, Ground, Neg. Seq.)
79 Reclosing
81 Frequency
85 SEL Mirrored Bits Communications
BRM Breaker Wear Monitor
DFR Event Reports
HBL Harmonic Blocking
HMI Operator Interface
LDE Load Encroachment
LGC SELogic Control Equations
MET High-Accuracy Metering
PMU Synchrophasors
RTU Remote Terminal Unit
SBM Station Battery Monitor
SER Sequential Events Recorder

* Optional


Front- and Rear-Panel Diagrams

SEL-451 Front Panel SEL-451 Rear Panel
Front Rear


Maximize the Capability of Substation Equipment

Fully load equipment by monitoring power, including thermal or rolling interval demand as well as peak demand on positive-,negative-, and zero-sequence current. Use the full capacity of the equipment while maintaining SEL quality protection.

Improve Operation With Built-In Real-Time Synchrophasor Measurements

Help system operators understand the network status with real-time visual displays of system phase angles and frequency. High-accuracy synchronized phasor measurements provide information and control to match the frequency and phase angle for critical activities, such as switching, startup, and power transfer.

Provide Powerful Bay Control and High-Speed Breaker Protection

Complete two-breaker control and breaker failure protection complement the versatility of the SEL-451 Protection, Automation, and Bay Control System programmable logic to meet your bay control needs. Easily control motor-operated switches, capacitor banks, and field I/O from the front panel or remotely.

Advanced Power System Monitoring

Provide advanced power quality monitoring of system disturbance information with voltage sag, swell, and interruption (VSSI) monitoring



451 351 351A 751 751A 551/
Distribution Feeder Protection
Breaker Failure Protection f f
Generator Intertie Protection + +
Synchronism Check + +
Underfrequency Load Shedding f
Undervoltage Load Shedding f +
27/59 Under-/Overvoltage +
32 Directional Power Elements f + +
49 Thermal Overload f
50 (P,N,G,Q) Overcurrent Element (Phase, Neutral, Ground, Neg. Seq.)
51 (P,N,G,Q) Time-Overcurrent Element (Phase, Neutral, Ground, Neg. Seq.)
67 (P,N,Q) Directional Overcurrent (Phase, Neutral, Neg. Seq.) +
81 Over-/Underfrequency
Separate Neutral Overcurrent
Load-Encroachment Supervision +
Mirrored Bits Communications +
Sensitive Earth Fault Protection + + +
Directional Sensitive Earth Fault Protection + +
Pilot Protection Logic
Rate-of-Change-of-Frequency (df/dt) f +
Harmonic Blocking +
Arc Sense Technology (AST) High-Impedance Fault Detection + +
Arc-Flash Detection + +
Phantom Phase Voltage
Current/Voltage Channels 6/6 4/4 4/4 4/4 4/4 4/0
Complete Two-Breaker Control
79 Automatic Reclosing + +
Fault Locating
SELogic Control Equations With Remote Control Switches
SELogic Counters
Voltage Check on Closing + +
Operator Control Pushbuttons
SELogic Nonvolatile Latch +
Nonvolatile Local Control Switches +
Display Points +
Multiple Settings Groups
Substation Battery Monitor + +
Breaker/Recloser Wear Monitor
Trip Coil Monitor f f f f f f
Voltage Sag, Swell, and Interruption (VSSI) +
Load/Signal Profile Recorder +
Sequential Events Recorder
Demand Meter +
DNP3 Level 2 Outstation + + +
Modbus Outstation +
IEEE C37.118 Synchrophasors
Bay Control
Ethernet + + +
IEC 61850 + + + + +
Simple Time Network Protocol (SNTP)
Independent Trip/Close Pushbuttons + + +
Harmonic Metering
RMS Metering
Standard Feature
+ Model Option
f This function may be created using settings

Product Literature