ABB Relion ® 615 series RED615 line differential protection and control device

Access range: Local (connected to laptop via front-end RJ-45 port) or remote (via LAN/WAN).

（3） User Authorization

Four types of user permissions are preset, with authorization disabled by default (WHMI mandatory), and passwords can be changed by administrators:

Typical operations within the scope of username permissions

VIEWER read-only view of measurement values and alarm logs

OPEROTOR control and status switching, local/remote mode switching, alarm reset

ENGINEER configuration and testing modify parameters, clear disturbance records, enter testing mode

Administrator full permission to change password and restore factory settings

Core functions and standard configurations

（1） Three standard configuration schemes

RED615 provides three predefined configurations that cover different ground fault protection requirements, with the following core differences:

Configuration Type Core Protection Function Applicable Scenarios Key Modules

Configure A (line differential protection), including line differential protection (87L), three-phase overcurrent protection (50P/51P), negative sequence overcurrent protection (46), and circuit breaker failure protection (51BF), for cable feeders. In scenarios where ground fault protection is not required, there is no zero sequence voltage input and the CT synthesis of zero sequence current is relied upon

Configuration B (including directional grounding fault protection) Configuration A: All functions+directional grounding fault protection (67N), transient/intermittent grounding fault protection (67NIEF), automatic reclosing (79). For overhead lines/cable mixed lines, it is necessary to distinguish the fault direction of the power grid (such as multi power distribution network), including zero sequence voltage input (U ₀), and adapt to the compensation grounding system

Configuration C (including non directional grounding fault protection) Configuration A: All functions+non directional grounding fault protection (50N/51N), automatic reclosing (79), radiation type distribution network, no need to distinguish fault direction scenarios (such as single power supply feeders) rely on CT synthesized zero sequence current, no zero sequence voltage input

（2） Detailed explanation of key protection functions

Line differential protection (LNPLDF1, 87L)

Core function: As the main protection, it realizes unit protection of the line and quickly cuts off internal faults;

Features: Contains stable low order (can be locked by CT fault detection) and instantaneous high order (can dynamically adjust the action value through remote circuit breaker status);

Communication dependency: It is necessary to establish protective communication with the remote IED, which will automatically lock in case of communication failure to avoid misoperation.

Earth fault protection

Directional (configuration B): Based on the phase of zero sequence current (I ₀) and zero sequence voltage (U ₀), the fault direction is determined, suitable for multi terminal power grids, divided into low order (sensitive section) and high order (fast section);

Non directional (configuration C): Based solely on zero sequence current amplitude action, suitable for single ended power grids, divided into low order, high-order, and instantaneous order.

Automatic reclosing (DARREC1, 79, configuration B/C optional)

Starting condition: triggered by protection action signals (such as overcurrent, ground fault);

Locking logic: The circuit breaker spring is not storing energy, the gas pressure is low, and it is locked when manually opening;

Status indication: LED5 is lit during the reclosing process, and an alarm is triggered when it fails.

Circuit breaker related protection and monitoring

Circuit breaker failure protection (CCBRBRF1, 51BF/51NBF): When the circuit breaker is not opened after the protection action, a trip command is sent to the upstream circuit breaker;

Trip Circuit Monitoring (TCSSCBR1/2, TCM): Monitor 2 sets of trip coil circuits, and lock the monitoring function when the circuit breaker is opened;

Circuit breaker status monitoring (SSCBR1, CBCM): Based on current and contact status, the mechanical characteristics of the circuit breaker are determined, and an alarm is triggered when there is an abnormality.

Communication and Networking

（1） Protocol support

Protocol type, functional scope, physical interface

IEC 61850 monitoring, control, parameter configuration, disturbance record upload (COMTRADE format), GOOSE message (trip level delay ≤ 3ms) Ethernet (RJ-45100BASE-TX)

IEC 60870-5-103 Protection signal upload, telemetry and remote signaling RS-485 or Ethernet

Modbus RTU/ASCII third-party device interconnection (such as PLC, SCADA) RS-485 or RS-232

DNP3 telemetry, remote signaling, remote control, supporting TCP/IP or serial Ethernet or RS-485

（2） Precautions for Communication Networking

GOOSE application: supports the highest performance level (transmission delay ≤ 3ms), meets the tripping requirements of distribution substations, and can simultaneously send events to 5 clients;

Client limitation: A single IED can support up to 5 concurrent clients. After PCM600 occupies 1, the remaining 4 can be allocated to other protocol clients;