SEL-487E Transformer Protection Relay



SEL-487E Transformer Protection Relay

High-speed transformer differential

protection for up to seven terminals

• Minimize damage and limit expensive repairs to transformers with

advanced differential protection and three restricted earth fault

(REF) elements.

• Consolidate protection schemes using a combination of differential,

distance, and overcurrent elements suitable for transformer, bus, line,

and feeder protection.

• Simplify engineering and reduce maintenance costs by using a single

device for pad-mounted switchgear applications.

• Benefit from comprehensive substation asset management with

through-fault, thermal, and circuit breaker monitoring.

• Transform and simplify the way you modernize your substation with

SEL Time-Domain Link (TiDL®) or Sampled Values (SV) technologies.

ANSI Number/Acronyms and Functions

16 SEC Access Security (Serial, Ethernet)

21* Phase and Ground Distance

24 Volts/Hertz

25 Synchronism Check

27 Undervoltage

32 Directional Power

46 Current Unbalance

49 IEEE C59.71- and IEC 60255-Compliant Thermal Model

50BF Dual Breaker Failure Overcurrent

50N Neutral Overcurrent

50 Overcurrent (Phase, Zero Sequence, Neg. Seq.)

51N Neutral Time Overcurrent

51 Time Overcurrent (Phase, Zero Sequence, Neg. Seq.)

59 Overvoltage

67 Directional Overcurrent (Phase, Zero Sequence,

Neg. Seq.)

68* Out-of-Step Block

79* Autoreclosing

81 Over-/Underfrequency

85 RIO SEL Mirrored Bits® Communications

87T Transformer Differential (Unrestrained, Restrained,

Neg. Seq.)

87B* Bus Differential (Restrained)

Additional Functions

BRM Breaker Wear Monitor

DFR Event Reports

ENV SEL-2600 RTD Module*

HBL Harmonic Blocking

HMI Operator Interface

LDP Load Data Profiling

LGC SELogic® Control Equations

MET High-Accuracy Metering

PMU Synchrophasors

REF Restricted Earth Fault

RTU Remote Terminal Unit

SBM Station Battery Monitor

SER Sequential Events Recorder

SIP Software-Invertible Polarities

SV IEC 61850-9-2 or IEC 61869-9 Sampled Values*†

TiDL Time-Domain Link Technology*†

TRM Transformer Monitor

Key Features

Multiwinding Protection

Configure the SEL-487E Transformer Protection Relay

for differential protection in transformer applications

using up to seven restraint currents. This includes single

transformers with tertiary windings. Three independent

REF elements offer protection for grounded-wye windings.

You can invert individual or grouped CT or PT polarities to

account for field wiring or protection zone changes.

High-Speed, Adaptive Differential Protection

Implement a two-stage slope that automatically adapts

to internal or external fault conditions, even with CT

saturation and heavily distorted waveforms, for fast,

sensitive, dependable, and secure differential protection.

The adaptive differential element responds to internal

fault conditions in less than 1.5 cycles. The SEL-487E

includes two differential elements: one intended for

protecting transformers and the other intended for

protecting busbar applications.

Diverse Applications

Simultaneously protect transformers, buses, lines,

and feeders in centralized protection applications.

Protect large transformers and autotransformers with

breaker-and-a-half high- and low-side connections. You

can configure the SEL-487E for a typical two-winding

transformer application and use the remaining three

phase current inputs for feeder or line backup protection.

Sensitive Turn-to-Turn Fault Detection

The patented negative-sequence differential element

detects turn-to-turn faults involving as little as

2 percent of the total winding, helping avoid catastrophic

transformer failure.

Configurable Distance Protection

Apply up to four zones of phase and ground distance

protection using mho or quadrilateral characteristics. The

SEL-487E distance elements can be applied as primary

transmission line or backup transformer protection.

Dependable Backup Protection

Provide backup protection with phase, negative

sequence, and zero-sequence overcurrent elements and

21 configurable time overcurrent elements. By setting up

breaker failure protection with subsidence detection, you

can rapidly detect breaker failure and minimize system

coordination times.

Generator Step-Up Transformer Protection

Protect generator step-up (GSU) transformers with built-in

temperature measurement (requires the SEL-2600 RTD

Module) that monitors generator and transformer winding

temperatures simultaneously. In addition, the volts/hertz

element provides overexcitation protection for loaded and

unloaded generator operating conditions. By setting the

directional power elements to detect forward and reverse

power flow conditions, you can monitor and protect the

GSU transformer in prime-power, standby, base-load, and

peak-shaving applications. Built-in synchronism-check

elements verify the generator breaker synchronization.

Advanced Asset Monitoring

Track transformer wear with through-fault and thermal

monitoring. Advanced breaker monitoring reduces

inefficient and costly breaker maintenance. You can also

monitor substation dc power systems for out-of-tolerance

voltage levels or excessive voltage ripple.

Station Phasor Measurement Unit (PMU)

Improve power quality with IEEE C37.118 synchrophasors

from all 18 analog channels (6 voltage and 18 current

sources) in your relay. Using synchrophasors over serial or

Ethernet communications, you can easily detect reactive

loop flows, turn state estimation into state measurement,

and provide early warning of potential system instability.

Real-time control is possible by receiving synchrophasor

messages from two PMUs, and you can take action based

on time-synchronized local and remote measurements.

Digital Secondary System Technologies

Modernize your substation by applying SEL TiDL or SEL

SV technology. Both of these digital secondary system

solutions replace copper wires with fiber-optic cables to

increase safety, reduce costs associated with using copper

wires, and limit the impact of electromagnetic interference.

TiDL is a simple and secure point-to-point solution that is

easy to implement, with no external time source or network

engineering required. SEL-TMU TiDL Merging Units placed

in the yard digitize signals and transmit them over fiber

optic cables to the SEL-487E-5 TiDL relay in the control

house.

SEL SV combines protection in the merging unit with the

f

lexibility of IEC 61850-9-2 or IEC 61869-9 protocols. SEL

SV merging units digitize signals and transmit them via

Ethernet over fiber-optic cables to SEL SV relays or other

manufacturers’ compliant relays in the control house.