ABB RET670 Transformer Protection Device

ABB RET670 Transformer Protection Device

Product positioning and application

RET670 is ABB Relion ®  The transformer protection device in the 670 series is mainly used for fast, selective protection, monitoring, and control of double winding, three winding transformers, autotransformers, generator transformer groups, and parallel reactors. Its design can adapt to a wide frequency range, cope with power grid disturbances and frequency changes during generator start stop, and is suitable for various circuit breaker configurations (single circuit breaker, multiple circuit breakers). It also provides six pre configuration schemes to meet different scenario requirements, such as transformer backup protection, voltage control, and the application of dual winding/triple winding transformers in single circuit breaker or multiple circuit breaker arrangements.Core 

Protection function

Differential protection

It includes dual winding (T2WPDIF) and triple winding (T3WPDIF) transformer differential protection, with automatic CT ratio matching and vector group compensation functions. It avoids excitation inrush current misoperation through second harmonic and wave blocking braking, and prevents overexcitation misoperation through fifth harmonic braking. It has high sensitivity to winding turn faults.

Low impedance limited ground fault protection (REFPDIF): As a supplementary protection for winding ground faults, it includes a zero sequence current direction criterion, with high sensitivity (as low as 5%) and rapid action.

High impedance differential protection (HZPDIF): can be used to limit ground faults or differential protection of autotransformers, tertiary reactors, etc., requiring external CT current summation, series resistance, and varistor coordination.

Impedance protection

Quadrilateral characteristic distance protection (ZMQPDIS, etc.): used for backup protection of transformer and connected power grid faults, supports multiple fault loops, can independently set directional or non directional modes, and has load intrusion detection function.

Mu Ou characteristic full range distance protection (ZMHPDIS, etc.): four zone protection, suitable for backup protection of lines and cables, supporting single pole automatic reclosing.

Current protection

Instantaneous/four step overcurrent protection: covering phase current, residual current, negative sequence current, etc., supporting direction and voltage control, providing multiple inverse time characteristic curves.

Thermal Overload Protection (TRPTTR): Based on a dual time constant thermal model, it estimates the internal temperature of the equipment and provides two-level warning and trip functions.

Circuit Breaker Failure Protection (CCRBRF): Quickly trip surrounding circuit breakers when the circuit breaker refuses to move, supporting current, contact, or adaptive criteria.

Other Protection

Voltage protection: including overvoltage (OV2PTOV), undervoltage (UV2PTUV), residual overvoltage (ROV2PTOV), etc., can be set with inverse time limit or definite time limit characteristics.

Frequency protection: including under frequency (SAPTUF), over frequency (SAPTOF), and frequency change rate (SAPFRC) protection, used for load shedding, power generation control, etc.

Overexcitation protection (OEXPVPH): prevents transformer/generator from overheating and damage due to high magnetic density, supports custom inverse time curve.

Control and monitoring functions

control function 

Synchronization Check and Synchronization (SESRSYN): Check the voltage synchronization on both sides of the circuit breaker, support manual and automatic reclosing, and adapt to dual busbar, ring busbar and other arrangements.

Equipment Control (APC): Used for controlling and monitoring circuit breakers, isolating switches, etc., supporting the "select execute" principle and providing command models for different safety levels.

Tap control (TR1ATCC, etc.): Automatically adjust the transformer tap to stabilize the secondary voltage, supporting control of single or multiple parallel transformers.

Monitoring and Recording

Measurement function: Real time monitoring of parameters such as voltage, current, power, frequency, etc., calculating positive sequence, negative sequence, and zero sequence components.

Event and disturbance recording: Built in disturbance recorder (DRPRDRE), records analog and switch data before and after faults, supports Comtrade format for easy fault analysis.

Counter and Measurement: The Pulse Counter (PCGGIO) records external pulses, while the Energy Calculation Function (ETPMMTR) calculates active/reactive energy and maximum demand.

Communication and Interface

Communication functions and protocols

RET670 has rich communication capabilities, supports multiple industry standard protocols, and can flexibly access automation systems at different levels, including:

Station level communication protocol

IEC 61850-8-1: Implemented through a single or dual channel fiber optic Ethernet interface (OEM module), supports GOOSE peer-to-peer communication, facilitates data exchange between intelligent electronic devices (IEDs) from different manufacturers, can upload perturbation files, and has a communication rate of 100BASE-FX.