For reliable protection and control of all types of power transformers and reactors
RET650 – your best choice for sub-transmission applications
RET650 offers optimum ‘off-the-shelf’, ready-made solutions for protection of two- and three-winding transformers, including voltage control for a single transformer. Additionally, a separate voltage control unit can handle two parallel operating transformers and integrate back-up protection functionality. The type tested variants of RET650 IEDs (Intelligent Electronic Device) are delivered equipped and configured with complete functionality and with default parameters for easy handling of products – from ordering, engineering and commissioning to reliable operation.
The 650 series IEDs introduce a number of innovations, such as significantly reduced parameter setting. In the 650 series IEDs, most basic parameters are set before delivery from the factory. You only need to set the parameters specific to your application. The parameters related to transformer protection are mostly set as a percentage of transformer ratings, which significantly reduces the need to re-calculate the current and voltage pickup values. This allows the IEDs to be quickly taken into operation. The application manual includes setting examples to support the protection engineer.
Unrivalled sensitivity and speed
The differential protection function in RET650 feature tap-changer position adaptation, which significantly increases the sensitivity of the IED. RET650 offer the best possible coverage for power transformer winding turn-to-turn faults, including low-level internal faults. The unique negative sequence internal/external fault discriminator is faster than a conventional stabilized transformer differential protection function. It also enables extremely sensitive protection to detect evolving internal faults so that the system can be tripped before a more severe fault with serious damages occurs. RET650 places low requirements on the main CTs and no interposing CTs are needed.
The low impedance restricted earth-fault function for all directly or low impedance earthed windings provides excellent stability for external faults. Having individual protection for each winding without the need for harmonics stabilization ensures high sensitivity and fast tripping. The additional directional zero sequence current criterion of this function increases security.
Non-directional and/or directional overcurrent functions provide the necessary back-up protection. This, together with fast and sensitive restricted earth-fault protection of stabilized low impedance types, with sensitivity down to 1% of the total number of turns, ensures comprehensive protection for your power transformers. The thermal overload function prevents transformer damage caused by overload. Breaker failure protection allows high speed back-up tripping of surrounding breakers and re-tripping of the own breaker, for instance, to avoid operational mistakes during testing.
RET650 provides you with a future-proof concept based on application flexibility, which makes it an excellent choice for both new and retrofit installations. The integration of the main protection and a wide range of back-up protection functions within the IED improve your power system performance. It also reduces engineering and installation time as well as space and spare parts requirements.
Both RET650 and RET670 IEDs provide fast and selective protection, monitoring and control for all types of transformers, such as two- and three-winding transformers, step-up transformers in power stations and special railway transformers.
Relion® – Complete confidence
Transformer protection RET670/650 IEDs belong to the Relion® protection and control product family. The Relion product family offers the widest range of products for the protection, control, measurement and supervision of power systems. To ensure interoperable and future-proof solutions, Relion products have been designed to implement the core values of the IEC 61850 standard. With ABB’s leading-edge technology, global application knowledge and experienced support network, you can be completely confident that your system performs reliably – in any situation.