ABB Relion ® REU615 Voltage Protection and Control Device

ABB Relion ®  REU615 Voltage Protection and Control Device

Product positioning and application

RET670 is a multifunctional protection, monitoring, and control device designed specifically for power transformers, autotransformers, generator transformer groups, and parallel reactors. It supports dual winding and triple winding configurations and is suitable for single circuit breaker and multi circuit breaker scenarios. Its core advantages include:

High speed differential protection: automatic CT ratio matching and vector group compensation, supporting up to 6 constrained CT inputs, suitable for complex power grid structures.

Broadband adaptability: able to operate stably even in the event of frequency fluctuations in the power system (such as generator start stop).

Modular design: supports multiple hardware configurations and software feature packages, adapting to new installations and old system renovations.

Core protection function

Differential protection

Dual winding/triple winding differential (T2WPDIF/T3WPDIF): equipped with second and fifth harmonic braking to prevent excitation inrush current and overexcitation misoperation, with high sensitivity to internal turn to turn faults.

Low impedance grounding fault protection (REFPDIF): For winding grounding faults, it includes zero sequence current direction criteria and supports different CT transformation ratios.

High impedance differential (HZPDIF): suitable for special scenarios such as autotransformers and tertiary reactors.

Backup protection

Impedance protection: quadrilateral and M-O characteristics, supporting phase to phase/ground faults, including load intrusion algorithm, suitable for high impedance faults.

Overcurrent protection: Four stage phase overcurrent and ground overcurrent, configurable for direction or voltage control, supporting inverse time/definite time characteristics.

Voltage/frequency protection: overvoltage/undervoltage, overclocking/underfrequency protection, supporting voltage differentiation and frequency change rate detection.

Auxiliary protection

Thermal Overload Protection (TRPTTR): Dual time constant model, monitoring transformer winding temperature, supporting alarm and trip.

Circuit Breaker Failure Protection (CCRBRF): detects the rapid tripping of adjacent circuit breakers when they refuse to move.

Oil pillow/pressure release protection: Connect gas relay and pressure release signal to achieve rapid response to faults.

Monitoring and control functions

measurement and metrology

Real time monitoring of voltage, current, power, frequency and other parameters, supporting harmonic analysis and power quality monitoring.

Disturbance Recorder (DRPRDRE): records waveforms before and after faults, supports exporting in COMTRADE format.

Control and regulation

Load tap changer control (TR1ATCC/TR8ATCC): Automatic voltage regulation, supports parallel operation of single or multiple transformers, and adapts to different voltage regulation strategies.

SESRSYN synchronization check: detects the synchronization status of voltage on both sides and supports grid connection operation.

Condition monitoring

Trip circuit supervision, CT/PT disconnection detection, tap changer position monitoring, supporting equipment health status assessment.

Communication and Interface

communication protocol

Supports IEC 61850-8-1 GOOSE/SMV, IEC 60870-5-103, Modbus, DNP3, and is compatible with substation automation systems.

Redundant communication supports IEC 62439-3 to enhance system reliability.

hardware interface

Input module: current/voltage input (1A/5A, 110V/220V), RTD/mA input (such as tap changer position).

Output module: 24 relay outputs, supporting tripping and signal alarm, some models include high-speed static output.

Hardware and Installation

Hardware Architecture

There are three chassis sizes: 1/2 x 19 inches, 3/4 x 19 inches, and 1 x 19 inches, which support DIN rail or panel installation.

Modular design: power module (PSM), binary input/output module (BIM/BOM), communication module (OEM/SLM), etc.

Environmental adaptability

Working temperature: -10 ℃~+55 ℃, storage temperature: -40 ℃~+70 ℃, protection level IP40 (front board).

Compliant with industry standards such as EMC, vibration, and shock, suitable for harsh substation environments.

Working principle

Principle of Protection Function

Differential protection: Dual winding/triple winding differential protection (T2WPDIF/T3WPDIF) monitors and compares the current on each side in real-time through automatic CT ratio matching and vector group compensation. When an internal fault is detected and the differential current exceeds the set value, the protection device quickly activates. At the same time, utilizing the braking characteristics of second and fifth harmonics effectively prevents misoperation caused by excitation inrush current and overexcitation. Low impedance ground fault protection (REFPDIF) is designed for winding ground faults. By measuring the current of each winding and combining it with the zero sequence current direction criterion, it achieves high-sensitivity ground fault detection. High impedance differential protection (HZPDIF) utilizes external CT current summation, series resistance, and voltage dependent resistance, suitable for specific protection scenarios such as tee feeders or bus protection.