ABB 1MRK0023505-AA Transformer Differential Protection Relay

ABB 1MRK0023505-AA Transformer Differential Protection Relay

Product Overview

ABB 1MRK0023505-AA is a high-precision differential protection relay designed specifically for the safe and stable operation of power transformers, belonging to ABB RELION ® Series protection device camp. As the core equipment of transformer main protection, its core function is to accurately identify serious faults such as internal short circuits and winding turn faults of transformers by real-time collection of high and low voltage side current signals and differential calculation. At the same time, it can reliably avoid misoperation in non fault scenarios such as excitation inrush current and external faults, quickly trigger protection actions to cut off the fault circuit, minimize damage to transformers caused by faults, and ensure the continuous and stable operation of the power system.

This relay integrates ABB’s advanced algorithms and digital technology in the field of power system protection, and has the characteristics of superior protection performance, fast action speed, strong anti-interference ability, and convenient human-computer interaction. It is widely used in oil immersed and dry-type transformer protection in power stations, substations, industrial enterprise distribution stations and other scenarios, and is a key equipment for building a strong power system protection system.

Core functions and protective features

1. Core protection function

-Core function of differential protection: Adopting a differential protection algorithm based on fault components, real-time collection of secondary currents from current transformers (CTs) on each side of the transformer, and calculation of differential current and braking current through phase compensation, ratio balancing, and other processing. When the differential current exceeds the set value and meets the braking characteristic criteria, it is judged as an internal fault, and a trip command is quickly issued. The action time can be as low as tens of milliseconds, effectively limiting the expansion of the fault.

-Excitation inrush current recognition function: Equipped with advanced excitation inrush current discrimination algorithms (such as second harmonic braking, intermittent angle braking, etc.), it can accurately distinguish the excitation inrush current after transformer no-load closing or external fault removal from the internal fault current, avoiding protection device misoperation and greatly improving the reliability of protection.

-Interturn short circuit protection function: For inter turn and inter layer short circuit faults in transformer windings, a special differential current analysis logic can accurately identify the fault at the early stage, especially suitable for early warning and rapid removal of large capacity transformer winding faults, reducing winding burnout losses caused by faults.

-Backup protection auxiliary function: integrates backup protection functions such as overcurrent protection and zero sequence current protection. When the main protection fails to operate due to some reasons, the backup protection can be used as a supplement to ensure that faults are effectively handled, forming a complete protection system of “main protection+backup protection”.

2. Additional practical features

-Digital communication capability: Supports mainstream power communication protocols such as IEC 61850, Modbus, DNP3.0, etc., and can seamlessly integrate into intelligent substation automation systems to achieve remote uploading and monitoring of protection information, fault recording data, and operating status parameters, facilitating centralized and intelligent management by operation and maintenance personnel.

-Complete fault recording function: With high-precision fault recording capability, it can record the waveform of electrical quantities such as current and voltage before and after the fault occurs, as well as device action information. The recorded data can be exported through the communication interface or viewed directly on the device, providing important basis for fault analysis and cause investigation.

-Flexible parameter configuration function: equipped with a Chinese LCD display interface and operation buttons, supporting flexible configuration of protection settings, logic functions, communication parameters, etc. on site; Simultaneously supporting offline configuration and parameter download through dedicated software, adapting to transformer protection requirements of different capacities and wiring methods.

-High reliability and anti-interference design: using industrial grade high stability components, the internal circuit has a complete overvoltage and overcurrent protection mechanism; The electromagnetic compatibility performance complies with the IEC 61000 series standards and can effectively resist surges, electromagnetic radiation, high-frequency interference, etc. in the power system, ensuring stable operation in complex electromagnetic environments.

Key technical parameters

Power parameters

DC power supply: 220V DC ± 20% or 110V DC ± 20%; AC power supply: 220V AC ± 20%; Power consumption: ≤ 15W

Adapt to commonly used AC/DC power sources in power systems, with strong voltage adaptability, to meet the power configuration requirements of different substations

Current input

Rated current: 5A or 1A (can be matched by CT ratio); Measurement accuracy: 0.2 level (protection accuracy: 0.5 level)

Compatible with mainstream CT secondary current specifications in the power system, with high measurement and protection accuracy, ensuring data accuracy

Voltage input

Rated voltage: 100V (line voltage) or 57.7V (phase voltage); Measurement accuracy: 0.2 level

Adapt to the secondary output voltage of voltage transformers (PT) to meet the requirements of voltage monitoring and related protection functions

Protection action time

Differential protection action time: ≤ 30ms; backup protection action time: can be flexibly set (minimum 100ms)

The main protection operates quickly and can quickly cut off faults; The backup protection time can be configured as needed to adapt to the system’s requirements

communication interface

1 Ethernet interface (supporting IEC 61850); 2-channel RS485 interface (supports Modbus/DNP3.0)

Supports multiple communication methods for easy access to different types of automation systems, enabling data exchange and remote control

Output contact

Trip output: 4 pairs (normally open); Signal output: 6 pairs (normally open/normally closed optional); Contact capacity: AC 250V/5A, DC 220V/2A

Satisfy the driving requirements of the trip circuit and signal circuit, and can directly control the circuit breaker trip coil and signal relay

working environment

Temperature: -25 ℃~+70 ℃; Humidity: 5%~95% (no condensation); Protection level: IP40 (device body)

Adapt to various installation environments such as outdoor terminal boxes and indoor control cabinets, and withstand a wide range of temperature and humidity

Installation method

35mm standard DIN rail installation or panel embedded installation

Supports two installation methods to adapt to different cabinet structures and installation space requirements

Typical application scenarios

The transformer differential protection relay is widely used in power systems and industrial fields due to its precise protection performance and strong adaptability. Typical scenarios include:

1. Power station transformer protection: used for the protection of main transformers in thermal power stations, hydropower stations, photovoltaic power stations, etc. As the core equipment connecting the power station to the grid, the relay can quickly cut off internal faults, ensuring the safety of power generation equipment and stable power output.

2. Substation Transformer Protection: Suitable for the protection of main transformers and distribution transformers in substations of all voltage levels (110kV, 35kV, 10kV, etc.), it is the core component of the substation protection system, ensuring that transformer faults do not spread and maintaining the reliability of power supply to the grid.

3. Industrial enterprise power distribution station: In the self owned power distribution stations of large industrial enterprises such as steel, chemical, metallurgical, and manufacturing industries, it is used to protect the internal power transformers of the enterprise, prevent transformer failures from causing production interruptions, and reduce economic losses of the enterprise.

4. New energy supporting transformer protection: Used in the boosting stations of wind power, photovoltaic and other new energy projects to protect the boosting transformers, ensure the stable connection of new energy power to the grid, adapt to the characteristics of large fluctuations in new energy power generation, and improve the reliability of protection.

Installation and maintenance precautions

1. Installation specifications

-The device should be installed in a well ventilated, non violent vibration, non corrosive gas, and non strong electromagnetic radiation control room or protective screen, avoiding direct sunlight and rainwater immersion. The ambient temperature and humidity should meet the requirements of the product’s working range.

-The current circuit, voltage circuit, power circuit, and communication circuit should be wired separately to avoid interference from strong current circuits to weak current circuits; The current circuit wiring should ensure correct polarity to avoid protection misoperation or refusal due to CT wiring errors.

-The wiring terminals should be securely fastened, especially for current circuit wiring, to avoid measurement errors or abnormal protection actions caused by poor contact; After the wiring is completed, insulation resistance testing and circuit on/off testing should be conducted to ensure that the wiring is correct and error free.

-The grounding of the device should comply with the grounding specifications of the power system, and the grounding resistance should be ≤ 4 Ω to ensure reliable grounding in case of faults, enhance the anti-interference ability of the device, and improve personal safety.

2. Maintenance points

-Regularly check the status of the device panel indicator lights and LCD display screen to confirm that the power supply is normal and the device has no fault alarms; Regularly check the communication status to ensure normal data exchange with the automation system.

-Conduct a comprehensive inspection of the device every six months to one year, including cleaning the surface of the device and the dust on the wiring terminals, tightening loose wiring terminals, and checking the stability of the output voltage of the power module.

-Regularly check the protection settings to ensure that they match the operating mode; Conduct a comprehensive test of the protective device once a year to verify the accuracy and reliability of the protective action.

-After the fault occurs, export the fault waveform data in a timely manner to assist in analyzing the cause of the fault; When the device malfunctions, professional technicians should be contacted for maintenance, and non professionals are prohibited from disassembling or modifying parameters on their own.