Several new features and functions are now available in Generator protection REG670.
Sensitive 100% stator/rotor earth-fault protection, injection-based
- 100% stator earth-fault protection using REX060 injection unit
- Sensitive rotor earth-fault protection using REX060 injection unit
When the injection-based protection of REG670 is used, 100% of the machine stator winding, including the star point, is protected under all operating modes, even at machine standstill. The innovative filtering technique enables high sensitivity for both stator and rotor protection, which enables early detection of faults.
Additionally, ABB’s innovative implementation of the injection principle allows the injection to be made always on the secondary side of either the voltage transformer or the grounding transformer. Therefore no changes need to be made in the machine primary circuit or grounding resistor. This enables very cost-efficient design of the injection unit, and makes it very easy and fast to take the protection system into operation. Thus REG670 offers an optimum solution for large hydro and turbo machines.
Negative sequence overcurrent protection for machines
The negative sequence overcurrent protection detects when machine operates with unbalance phase currents. It features high sensitivity, which enables detection of very low unbalance current level. Definite time delayed or inverse time delayed characteristic in accordance with synchronous machine capability are available.
Accidental energizing protection for synchronous generator
The accidental energizing protection detects if a generator is connected to the power system by mistake or due to a failure in the primary or secondary equipment. It uses voltage supervised overcurrent measurement in order to detect this very dangerous operating condition.
Improved disturbance recorder
The maximum pre-trigger recording time of the built-in disturbance recorder has been increased from one second up to 9.9 seconds. This is particularly useful in generator protection applications where it is important to record current and voltage waveforms before the trip signal has been given since the set operating times of the various protection functions can typically be fairly long.
Redundant station bus communication according to IEC 62439-3 PRP
Relion® 670 series IEDs support IEC 62439 standard redundant communications on the station bus. The solution from ABB utilizes the IEC 62439-3 standardized Parallel Redundancy Protocol (PRP). PRP improves the communication system reliability and features a unique capability of zero seconds’ recovery time in case of communication failures. This means that there will be no interruption in communication if one link fails as the other link instantaneously takes over the communication. As a result, there is no data lost when communication failures have occurred.
Also new hardware modules are available:
- A/D module with one microsecond accuracy in time synchronization
- New GPS clock module
- Transformer input module with three metering CTs, four protection CTs and five VTs
- Static binary output module for high-speed tripping with 30 A making capacity
- Binary input modules BIM and IOM with 50 mA pick-up current sink
For more information about Generator protection REG670, please refer to the Generator protection REG670/650 brochure and REG670 Product Guide.