Description

The ABB RET670 is a highly sophisticated and fully integrated protection and control IED (Intelligent Electronic Device) from ABB’s flagship RELION® 670 series, specifically engineered for the comprehensive management and security of power transformers. As a dedicated transformer protection terminal, the ABB RET670 provides a multi-functional platform that combines advanced differential protection, sophisticated backup protection functions, and extensive control and monitoring capabilities in a single, compact unit. It is designed to be the primary protective system for two-winding and three-winding power transformers of all criticality levels, from large utility transmission networks to major industrial power plants and distribution substations. The relay’s core function is to detect internal faults with extreme speed and sensitivity using its percentage-restrained differential protection, while its extensive suite of additional functions guards against external system disturbances and transformer-specific anomalies.

The ABB RET670 represents a significant leap in substation automation, fully embracing the digital substation concept with native support for IEC 61850-8-1 (GOOSE and MMS) and IEC 61850-9-2 LE process bus. This allows the ABB RET670 to communicate seamlessly with merging units for sampled values and other IEDs within the substation, drastically reducing copper wiring and enabling more flexible and interoperable system architectures. Beyond protection, the ABB RET670 performs high-accuracy measurement, extensive condition monitoring, and detailed event recording, providing a wealth of data for asset management and operational decision-making. Its robust design and powerful processing capabilities make the ABB RET670 an indispensable component for ensuring the safety, reliability, and efficiency of the power grid.

Technical Specifications

Main Features and Advantages

Advanced Differential Protection and Stabilization: The cornerstone of the ABB RET670 is its highly secure and sensitive transformer differential protection. It incorporates advanced algorithms to manage challenges such as transformer inrush currents, overexcitation, and CT saturation, ensuring it remains stable during these conditions while operating instantaneously for internal faults. The inclusion of both high-impedance and low-impedance differential options provides application flexibility. The relay’s powerful signal processing enables harmonic restraint, which reliably blocks operation during magnetizing inrush currents that contain high levels of second harmonics, a critical feature for preventing false trips during transformer energization.

Comprehensive Transformer-Specific Protection: The ABB RET670 goes far beyond basic differential protection by including a complete set of functions tailored to the physical phenomena that affect transformers. This includes thermal overload protection based on dual time-constant models for the oil and winding, overexcitation (V/Hz) protection to prevent damage to the core, and restricted earth-fault protection for increased sensitivity to internal ground faults. The integration of these functions into a single IED, the ABB RET670, ensures a coordinated and holistic protection strategy that is simpler to engineer and manage than a system composed of multiple discrete relays.

Full Digital Substation Integration: As a leader in the digital substation space, the ABB RET670 is built for the future. Its native support for IEC 61850-9-2 LE process bus allows it to receive digitized current and voltage samples directly from merging units, eliminating conventional analog wiring and its associated errors and costs. The use of GOOSE messaging enables high-speed, peer-to-peer communication with breaker failure relays, busbar protection, and other bay controllers, facilitating the implementation of complex, distributed protection schemes. This makes the ABB RET670 a cornerstone of modern, efficient, and reliable substation automation systems.

RET670 ABB

RET670 ABB

Application Field

The ABB RET670 is deployed wherever large, critical power transformers are located. In the utility transmission and sub-transmission sector, it is the protection system of choice for autotransformers and phase-shifting transformers at key substations, ensuring grid stability and preventing the widespread outages that can result from transformer failure. In power generation, the ABB RET670 protects the vital generator step-up (GSU) transformers that connect power plants to the grid, safeguarding a primary revenue-generating asset.

For large industrial complexes, such as steel mills, petrochemical plants, and data centers, the ABB RET670 provides protection for the main incoming transformers and critical inter-bus transformers, ensuring process continuity and protecting against massive financial losses from unexpected downtime. Its robust communication capabilities make it ideal for integration into industrial microgrids and energy management systems. The versatility and high performance of the ABB RET670 make it applicable in any scenario where transformer reliability is paramount to operational and financial success.

Related Products

ABB REG670: Generator protection relay, often applied in the same power plant as the RET670 for GSU transformer protection.

ABB REL670: Line differential protection relay, used for protecting transmission lines connected to the transformer.

ABB REB670: Busbar protection relay, providing the primary protection for the substation bus to which the RET670-protected transformer is connected.

ABB REC670: A controller version in the 670 series, which can handle automation and control tasks while the RET670 focuses on protection.

ABB RED670: A specific version for breaker failure and other auxiliary protection, often used in conjunction with the RET670.

ABB REX640: A protection and control system for various applications, representing another modern platform from ABB.

ABB PCM600: The universal configuration and monitoring software used to set parameters, analyze data, and manage the ABB RET670.

Installation and Maintenance

Pre-installation preparation: Prior to installing the ABB RET670, a thorough review of the system design, including CT/VT parameters, transformer nameplate data, and the single-line diagram, is essential. The panel layout must provide adequate space, ventilation, and proper cable entry. For systems utilizing process bus, the network architecture for the IEC 61850-9-2 LE communication must be meticulously planned. Engineers must have the PCM600 software and the appropriate device description (CID) file for the ABB RET670 ready for configuration before energization.

Maintenance recommendations: To ensure the long-term reliability of the ABB RET670, regular maintenance should include verifying the health of the DC power supply and checking the status of the relay’s self-supervision system. Periodically downloading and archiving event reports and disturbance records from the ABB RET670 is crucial for analyzing system events and verifying relay performance. While the relay itself is highly reliable, secondary injection testing during planned outages is recommended to validate the entire protection chain, including CT circuits and the relay’s internal logic. Firmware updates for the ABB RET670 should be applied with caution, always backing up the full configuration beforehand.