ABB REF 541, REF 543, and REF 545 feeder terminals

ABB REF 541, REF 543, and REF 545 feeder terminals

Product overview

REF 541, REF 543, and REF 545 feeder terminals are equipment developed by ABB for the protection, control, measurement, and monitoring of medium voltage power grids, and are part of ABB's substation automation system. They can adapt to different types of switchgear (such as single bus, double bus, and duplex systems) as well as multiple network types (such as neutral insulation networks, resonant grounding networks, and partial grounding networks), and can also be applied to the protection and control of medium-sized three-phase asynchronous motors and parallel capacitor banks for reactive power compensation. The main difference between these three devices lies in the number of digital inputs and outputs.

Core functions

Protection function

It includes multiple types of protection, such as non directional and directional overcurrent and ground fault protection, residual voltage protection, overvoltage and undervoltage protection, thermal overload protection, circuit breaker fault protection, and automatic reclosing.

The protection function based on current measurement can use Roche coils or traditional current transformers, while the protection function based on voltage measurement can use voltage dividers or voltage transformers.

control function 

Support local and remote control of switchgear, status indication of switchgear, and interlocking at interval and station levels.

Measurement function

Capable of measuring phase current, phase to phase and relative ground voltage, residual current and voltage, frequency, power factor, active and reactive power, and electrical energy.

The standard configuration includes pulse counter inputs, with varying quantities depending on the model (7 for REF 541 and 10 for REF 545).

Status monitoring function

Including circuit breaker status monitoring, trip circuit monitoring, and internal self-monitoring of feeder terminals.

Other functions

Such as synchronous inspection, frequency protection, capacitor bank protection and control, current and voltage harmonic measurement, etc.

Equipped with RTD/analog modules for temperature measurement, current/voltage measurement, and mA output.

Data recording and communication

Transient disturbance recorder: capable of recording 16 current or voltage waveforms and 16 logical digital signals, with a sampling frequency of 2kHz at rated frequency 50Hz and 2.4kHz at 60Hz. The recording can be uploaded and converted to COMTRADE format.

Communication: Provides two communication interfaces, one for local communication with PC and the other for remote communication through substation communication system, supporting SPA and LON serial communication protocols.

Software and hardware configuration

Hardware

Analog channels: Depending on whether sensors are included, there are 9 (no sensors) or 10 (with sensors) analog channels, as well as virtual channels for calculating neutral current and residual voltage.

Digital input: voltage controlled and optically isolated, partially programmable as a pulse counter, with a pulse counting frequency of up to 100Hz, and two global parameters for suppressing digital input oscillations.

Digital output: divided into high-speed power output (HSPO), power output (PO), and signal output (SO).

Display panel: equipped with a fixed display screen or external display module, the display panel includes multiple buttons and indicator lights for operating and indicating device status.

Software

It can be configured through the CAP 505 relay product engineering tool, including basic terminals, protection and logic function blocks, control and measurement functions, etc.

Support the use of relay configuration tools to program PLC functions (such as interlocking and alarm logic), using functional block diagram language.

Technical Parameter

Environmental conditions: The specified working temperature range is -10...+55 ° C, the transportation and storage temperature range is -40...+70 ° C, the front protection level of the shell is IP 54, and the back connection terminal is IP 20.

Power supply: There are two basic versions of power modules, PS1 and PS2, and the input voltage and operating range vary depending on the model.

Input and output parameters: including voltage, current range, and accuracy of digital input and output, analog input and output, etc..

Application scenarios

Suitable for various application scenarios of medium voltage power grids, such as different types of switchgear and networks, as well as protection, control, and monitoring of medium-sized three-phase asynchronous motors, parallel capacitor banks, etc. Specific application examples include utility incoming lines, feeders, measuring cabinets, ring/mesh network cable feeders, etc.

Major function 

Protection function: With multiple types of protection, it can comprehensively ensure the safety of the power system. In terms of current protection, overcurrent directional protection has 8 thresholds with freely programmable tripping characteristics, ground fault directional protection has 2 thresholds, and ground fault directional fan-shaped protection has 10 thresholds, which can accurately detect and respond to abnormal current situations. Voltage protection can monitor and protect the system voltage, preventing damage to equipment caused by overvoltage or undervoltage. It also covers differential protection, power direction protection, distance protection, etc., which can be used to protect multiple system components and provide reliable protection solutions for different types of faults. In addition, functions such as automatic reclosing, frequency monitoring, synchronization detection, and fault recording have further enhanced the stability and reliability of the system.

Control function: Supports multiple operating state switches, including running, testing, setting state switches, as well as local and remote state switches, making it convenient for operators to flexibly control equipment according to actual needs. Equipped with closing, opening and emergency opening functions, ensuring effective control of the equipment in different situations. Various interlocking functions are set up in the software, and the interlocking functions implemented through software settings can effectively prevent misoperation and ensure the safety of equipment and personnel.

Measurement function: It can accurately measure various electrical parameters, including three-phase current, zero sequence current, maximum demand for three-phase current, three-phase/line voltage, zero sequence voltage, active/reactive power, active/reactive electricity degree, power factor, frequency, etc. The measured values can be displayed on the LCD screen as numbers and LED bar charts, visually presenting the system's operating status and providing accurate data reference for operators.

Communication function: Supports multiple communication protocols such as RS485, Modbus, IEC 61850, DNP3.0, etc., and can exchange data with different devices and systems. Adopting fiber optic connection, it has the characteristics of simple wiring, strong anti-interference ability, and high reliability, which can achieve real-time information processing and perfect system management, facilitate networking, and meet communication needs in different scenarios.

Monitoring and diagnostic functions: capable of effectively monitoring primary equipment, such as monitoring spring charging time (when applicable) and trip coils, to promptly identify potential equipment issues. Equipped with a self diagnostic program that can continuously check the status of hardware and software modules. The binary input and output module is equipped with watchdog contacts, which are triggered in the event of a fault or power outage. The analog input channel can be selected for monitoring, detecting disconnection from the instrument transformer or sensor connection, and triggering an alarm.

Power quality function: It can monitor and analyze the power quality of the power system, provide data support for optimizing power quality, and ensure that the power system provides high-quality power for various equipment.

PLC function: Standardize the wiring of switchgear, simplify production management, reduce the types of spare parts, and facilitate on-site management and operation maintenance. Through flexible software development, engineering design can be simplified, design cycles can be shortened, on-site debugging efficiency can be improved, and it is easy to change the function of the switchgear or adapt to different load properties in the future.