Description
RET670 is a transformer protection measurement and control device (IED) in the ABB Relion series, designed to provide fast and selective protection, monitoring, and control for various power transformers and shunt reactors. It is the flagship model in ABB’s transformer protection product line, positioned higher than RET615/RET650.
ABB RET670 Transformer Protection IED 1MRK002816-AB
In terms of protection function, differential protection is the core highlight, with extremely fast action speed and low impedance. It has very low requirements for the main CT and does not require auxiliary CT. It has automatic CT ratio matching and vector group compensation functions, and supports multiple circuit breaker arrangements with up to 6 current inputs. Differential protection includes second harmonic and waveform block suppression for excitation inrush current braking, fifth harmonic suppression for overexcitation braking, and sensitive differential based on amplitude measurement and directional comparison of negative sequence components, which can detect low-level internal faults. Ground fault protection provides multiple low impedance limited solutions, including internal/external fault discriminators to improve safety, and also supports high impedance differential protection, which can be used for winding protection, autotransformer differential protection, parallel reactor protection, T-type feeder protection, busbar protection, and generator differential protection. Backup protection includes distance protection (Ohmic circle and quadrilateral characteristics, with load impedance intrusion detection and phase selection function), positive sequence negative sequence zero sequence overcurrent (optional direction and/or voltage control, four sections in total), instantaneous phase current and zero sequence current protection, thermal overload (dual time constant), circuit breaker failure protection, three-phase inconsistency protection, directional low power and directional over-power protection. In addition, there are two sections of low voltage, two sections of three-phase overvoltage, two sections of zero sequence overvoltage, overexcitation, voltage differential, voltage loss detection, and over frequency/low frequency/frequency change rate protection. Special functions include pole slip protection, which can detect and evaluate pole slip in the power system and take measures, as well as synchronous detection for grid control. The trip alarm signals from pressure relief, Buchholz, and temperature devices can be directly connected through high anti-interference binary inputs to prevent DC system capacitor discharge or ground faults from causing misoperation.
In terms of measurement and monitoring, it provides the ability to connect 40 analog signals and 96 switch signals, with high accuracy in analog measurement, power value error less than 0.5%, voltage and current value error less than 0.25%, and can be calibrated and optimized on site. Built in interference and event recorders are used for post fault analysis, supporting maximum required power calculation, and power values can be calculated separately for input and output.
In terms of communication, based on the IEC 61850 standard design, it supports the process bus IEC 61850-9-2LE and can be equipped with up to 6 merging units (MU). Native support for both LON and SPA buses. Time synchronization supports IEC 61850-8-1 (LON), SPA, switch input, or GPS/IRIG-B modules.
In terms of configuration and hardware, tuning, waveform analysis, and user settings are carried out through PC software tools, supporting 6 independent tuning value groups with password protection. Advanced logic functions can be programmed into user logic through graphical tools, enabling special applications such as automatic opening of isolation switches, closing of circuit breaker loops, and load transfer in multi circuit breaker arrangements, and supporting real-time online monitoring and debugging. The working temperature ranges from -25 ℃ to+70 ℃, with a protection level of IP20. It is equipped with a graphical LCD panel that supports local operation. The standard configuration includes a binary input module and a binary output module, which can be expanded according to the application.
Application industry:
Protection of main transformers and contact transformers for power supply companies in various provinces, cities, and counties under the State Grid Southern Power Grid in the power utility industry; In the petroleum and petrochemical industry, transformer protection for refineries and oil field substations of PetroChina, Sinopec, and CNOOC; Main transformer protection for non-ferrous and ferrous metal mines in the mining and metallurgical industry, and protection for electric furnace transformers in steel plants; The main transformer protection for large cement groups such as Conch China Resources in the cement and building materials industry; Protection of phase-shifting transformers and special railway power supply transformers in the rail transit industry, subway and national railway traction substations; Protection of step-up transformers and generator sets in the renewable energy industry, wind farms, and photovoltaic power plants; Protection of medium and high voltage main transformers in large industrial enterprises, papermaking, food and beverage industries.
Usage scenario:
1、 Two winding and three winding main transformer protection serve as the main and backup protection for main transformers in 110kV to 500kV substations. Differential protection quickly eliminates internal faults, while distance and overcurrent protection serve as backup; 2、 Autotransformer protection, suitable for autotransformers in substations of 500kV and above, high impedance differential protection can distinguish between internal and external faults in windings; 3、 Generator transformer protection, providing a complete set of differential, overcurrent, overexcitation, frequency abnormality and other protections for the generator transformer unit in the power plant, adapting to frequency changes during generator start stop periods; 4、 Parallel reactor protection, providing fast differential and ground fault protection for reactive power compensation parallel reactors; 5、 Phase shifting transformer protection, used for phase shifting transformers in railway traction substations, and pole slip protection can operate correctly during system oscillation; 6、 Transformer protection with multiple circuit breakers, supporting up to 6 current inputs, suitable for transformer protection with complex main connections such as one and a half circuit breakers; 7、 Wind power photovoltaic step-up transformer protection, adapted to the overexcitation, low-frequency, and differential protection requirements of main transformers in new energy stations; 8、 Comprehensive protection for overcurrent, grounding, thermal overload, and differential of medium voltage main transformers for high-power loads such as mining crushing stations, cement mills, and paper machines in large industrial enterprises.
Summary in one sentence: RET670 is ABB’s flagship protection and measurement device for various transformers and reactors, with fast low impedance differential and multiple backup protection, pole slip and full communication protocol as the core. It has extremely low requirements for CT and supports up to 6 current inputs. It is widely used in power utilities, petroleum and petrochemical, mining and metallurgy, cement and building materials, rail transportation, renewable energy and large industrial enterprises, covering full scene protection of main transformers, autotransformers, generator sets, parallel reactors, phase-shifting transformers, etc.
