ABB Transformer Protector RET670 Controller Accessories

Applications

The RET670 provides fast, selective protection, monitoring and control of two- and three-winding transformers,

autotransformers, step-up transformers and generator transformer sets.

transformer units, phase shifters, special railroad transformers and shunt reactors.

This IED operates normally over a wide frequency range to accommodate power system frequency changes during disturbances, generator startup and shutdown.

The RET670 features fast, low-impedance differential protection with very low CT requirements.

Differential protection function

Differential protection features 2nd harmonic and waveform block suppression to avoid CT

saturation and transformer inrush current tripping, as well as 5th harmonic suppression.

It also has a 5th harmonic suppression function to avoid transformer overexcitation trips.

Differential functions provide high sensitivity to low-level internal faults through the use of

sensitive differential protection based on amplitude measurement of the negative sequence component and direction comparison.

A variety of low impedance restricted earth fault protection functions are available as sensitive and fast primary protection against winding earth faults.

This function includes an internal/external fault discriminator for increased safety.

In addition, it has a high-impedance differential protection function. 

It can be used for different applications that 

These include limiting earth fault protection as winding protection, autotransformer differential protection,

shunt reactor protection, T-feeder protection, busbar protection and generator differential protection.