Description
ABB REF615 Feeder Protection Relay
REF615 Feeder Protection Relay Introduction
1. General Overview
REF615 is an integrated multifunctional feeder protection and control relay developed for medium voltage distribution network applications. It combines feeder protection, electrical measurement, bay control, fault recording and substation communication functions into a single compact unit, replacing multiple separate traditional secondary devices. This relay fits indoor distribution substations, industrial power systems, new energy collection stations and commercial power supply systems, serving overhead lines, underground cables and medium voltage auxiliary feeders. It supports flexible functional configuration to match different network structures including radial networks, loop networks and weakly meshed distribution grids.
ABB REF615 Feeder Protection Relay
2. Main Protection Functions
The relay provides a complete set of feeder-oriented protection algorithms with adjustable parameters and characteristic curves:
- Phase overcurrent protection, supporting definite time and multiple inverse time curves for selective coordination
- Residual overcurrent and sensitive earth fault protection for cable and overhead line ground fault detection
- Negative sequence overcurrent protection to identify phase unbalance, broken conductors and asymmetrical short circuits
- Thermal overload protection to monitor cable and equipment heating conditions and issue pre-alarms or trips
- Under voltage, over voltage, under frequency and over frequency protection for grid stability monitoring
- Directional overcurrent and directional earth fault functions for loop and ring main networks
- Configurable auto-reclosing logic with multiple shot sequences to restore power after transient faults
- Fault locator function that calculates fault distance based on measured voltage and current data
- Trip circuit supervision to detect broken trip coils or disconnected secondary wiring
- Cold load pickup logic to avoid false tripping during feeder re-energization
3. Measurement and Monitoring Functions
- Three-phase current, three-phase voltage and neutral residual current measurement
- Calculation of active power, reactive power, apparent power, power factor and grid frequency
- Accurate active and reactive energy accumulation for power statistics
- Harmonic measurement to monitor power quality distortion caused by nonlinear loads
- High-resolution time-stamped event logging to record all state changes, protection operations and alarms
- Fault waveform recording to capture pre-fault and post-fault voltage and current waveforms for post-fault analysis
- Support for external RTD sensor connection to monitor temperature of cables, transformers and switchgear
- Continuous status monitoring of circuit breakers, disconnectors and earthing switches via binary inputs
- Built-in self-supervision that monitors internal hardware and logic, generating alarms for component failures
4. Control and Logic Functions
- Local and remote control of circuit breakers, disconnectors and earthing switches
- Customizable switchgear interlock logic to prevent hazardous misoperation sequences
- Flexible programmable logic blocks to realize user-defined bay control logic without additional wiring
- Configurable load shedding and voltage regulation logic for distribution feeders
- Sequential event recording to track the sequence of switching and protection actions
- Test mode for on-site commissioning, allowing separate verification of protection, input and output circuits
5. Human-Machine Interface
A built-in front panel HMI simplifies on-site operation and inspection:
- Monochrome LCD display for viewing measured values, fault records, protection settings and device status
- Multi-color LED indicator lights showing running status, fault alarms and trip signals
- Physical operation pushbuttons for local breaker control, menu navigation and fault reset
- Local password access control to restrict unauthorized modification of protection parameters
6. Communication Capabilities
The relay supports mainstream industrial and substation automation communication protocols:
- IEC 61850 Ethernet communication for modern digital substation systems, including peer-to-peer GOOSE messaging
- Modbus TCP over Ethernet and Modbus RTU over serial ports for legacy SCADA integration
- IEC 60870-5-103 serial communication for traditional substation control systems
- Real-time uploading of measured values, event logs, fault records and alarm signals to central control platforms
- Remote parameter setting, firmware upgrade and fault data retrieval via communication channels
- Multi-level password protection to secure remote access and configuration changes
7. Mechanical and Environmental Features
- Standard panel-mount enclosure designed for installation inside medium voltage switchgear cabinets
- Wide-range auxiliary power supply compatible with both AC and DC substation auxiliary power sources
- High electromagnetic compatibility performance to resist interference from switching surges, short-circuit transients and nearby power equipment
- Dust and moisture resistant front panel suitable for standard indoor substation environments
- Stable continuous 24-hour operation with long service life and low maintenance demand
- Compact overall size to save valuable cabinet installation space
8. Typical Application Scenarios
- Medium voltage overhead distribution feeders in urban and rural power grids
- Underground cable feeders for residential and commercial distribution networks
- Medium voltage auxiliary power feeders in manufacturing plants and thermal power facilities
- Collector feeders for photovoltaic power stations and wind farm booster stations
- Ring main unit and distribution substation bay integrated protection and control units
9. Core Advantages
- All-in-one integrated design reduces the number of secondary devices and simplifies secondary wiring layout
- Fully software-configurable protection and logic functions without hardware replacement for most application adjustments
- Comprehensive fault data storage and analysis tools shorten troubleshooting time after grid faults
- Independent local HMI allows on-site inspection and testing without external laptops
- Excellent interoperability with various substation automation and SCADA systems
- Built-in self-monitoring minimizes unexpected device outages and reduces routine inspection workload
