Busbar Protection
ED7-B

The ED7-B series IEDs provide one integrated platform for the protection of busbars up to 765 kV. The IEDs are based on long-term field experience and focusing on the challenges our customers face.

Two versions are available:

Three-phase version with rigid connection diagram and maximum 8 protected bays
One-phase version with flexible connection diagram and maximum 24 protected bays

Front panel

Large graphic display is designed to show the information necessary for the user

16 electronic switches are used to enable/disable relay protection functions directly from the device front panel. Each electronic switch is fitted with LED indicator. They can be assigned to any program switch in IED logic circuit

The user assigns available versions:

32 LEDs with electronic switches,
48 LEDs w/o electronic switches.

These LEDs light up, when certain protections actuate. They can be freely configured for any internal logic signal

The following buttons are provided on the IED front panel:

alarm reset
local/remote control
selecting group of settings
keyboard

USB port for PC connection for setting up and configuring IED parameters

Rear view

Up to 160 binary inputs and output relays in total. Binary inputs have no common contact

IED has up to 32 analog inputs in various configurations

IEDs have several communication interfaces (RS-485, FOL, Ethernet (electrical/fiber-optic), 1PPS) and can be integrated into automation system of any enterprise

ED7-B protection function	ANSI code

Busbar differential protection	87B
Undervoltage protection	27
Overvoltage protection	59

Tripping logic	94
Breaker failure protection	50BF
CT Supervision

Three-phase Measurement
One-phase Measurement

Disturbance recorder
Event recorder
Self-test function

Application

It contains

a busbar differential protective relay with bias,
overvoltage and undervoltage relays that respond to phase-to-phase busbar voltages,
overvoltage and undervoltage relays responsive to busbar negative-sequence voltages,
circuit serviceability supervision relay,
busbar differential protection “sensing” logic,
testing logic,
AR inhibitor logic,
tripping circuit,
circuits of circuit-breaker failure protection start,
circuits of AR inhibitor logic.

Protection of four busbar sections is implemented

Busbar differential protection (BDP) relay

The protection is phase-by-phase and contains BDP relay, which responds to all types of busbar short circuits. BDP relay is connected to current transformers of all bays of protected busbars. When BDP trips, the trip signals are sent to output relays, that generate circuit-breaker tripping commands

Equalization of CT transformation ratios

Differences in transformation ratios of current transformers of the bays can be equalized

Sensitive current function relay

For reliable tripping of busbar circuit-breakers during BDP operation, including in busbar AR cycle, sensitive current function relay is provided, which responds to differential current of the starting element

CT supervision relay

CT supervision relays are provided on each phase in the cabinet. They supervise the phase differential currents of both selective and starting element

Self-test and test mode

Devices feature an advanced self-test system, ensuring continuous monitoring of hardware and software serviceability

Operation conditions

Devices operate at increased air humidity (≤ 80%), high positive and negative ambient temperatures (from -5 to +55 °C). Devices remain operable within 150 ms after power loss

Data communication protocols

Supporting all modern protocols, communication standards (IEC 61850-8-1, IEC 61850-9-2LE, IEC 60870-5-103, Modbus RTU (with optional converter) and time synchronization protocols (SNTP, PPS (electrical and optical), PTPv2 (for SV))

Specification	Value

Rated alternating current, A	1 or 5 (selected via software)
Rated frequency, Hz	50
Rated AC voltage, V	100
Rated auxiliary DC voltage, V	110; 220

Operational voltage range	-20 % … +10 %
Interruption, ms	150

Maximum continuous air temperature, °C	+55
Minimum continuous air temperature, °C	-5
Upper humidity value, %	80
Ingress protection (IP) degree	IP40 — front panel IP20 — rear panel

Permissible overload of current inputs, continuous	2 * I_r
Permissible overload of current inputs, 1s	100 * I_r
Burden at I_r, VA	0,2
Permissible overload of voltage inputs, continuous	1.5 * U_r 1.8 * U_r for open delta
Burden at U_r, VA	0,2

Rated voltage	(1-300) VDC (1-400) VAC
Continuous current, А	5
Switching capacity of contacts (making current)	up to 30 А for 0.20 s
Maximum operation time, ms	10

Busbar ProtectionED7-B

Display

Electronic switches

Two-color LEDs

Functional control

USB port

Binary inputs and output relays

Analog inputs

Communication ports

Functions

Features

Specifications

Busbar Protection
ED7-B