REG670 IED (Intelligent Electronic Device) provides protection and monitoring for generators, prime movers and step-up transformers in hydro-, pump-storage-, gas-, combined cycle-, steam- and cogeneration stations. With excellent performance, flexibility and scalability it fulfils the demanding requirements, in every corner of the world, for both new installations and retrofits.
Based on Hitachi Energy's extensive experience, REG670 takes generator protection to a new performance level. Up to 24 analog inputs permit integration of main and back-up protection in one IED. Alternatively, additional objects, such as transformers, can be included in the generator protection scope. This enables full duplication of the protection in main one and main two. These features allow a reduction of the number of IEDs needed to protect the entire generating station, increasing availability at the same time. This, in turn, simplifies the installation and reduces its lifecycle cost as related to commissioning, maintenance and spare parts. REG670 functionality also incorporates intelligent fault criteria, ensuring unrivalled selectivity and sensitivity.
Using an advanced and innovative filtering technique, REG670 can also provide integrated sub-synchronous resonance protection for turbo generators.
A generator protection scheme with REG670 meets the requirements for maximum dependability and availability. The generator differential protection features extremely fast detection criteria, with a typical operate time of 15 ms; while maintaining high security.
Among the many available functions, REG670 can include injection-based 100% stator and rotor earth-fault protection as well as 3rd harmonic based 100% stator earth-fault protection. These solutions enable a new way to optimize the cost-performance ratio of the protection system in relation to the importance or size of the generating station. Hitachi Energy's innovative implementation of the injection principle allows injection via a neutral point VT or even via an open-delta VT located at the generator terminals. As no changes need to be made in the primary circuit or in the grounding resistor, the design, installation and commissioning of the protection system is easy and fast. The 3rd harmonic based 100% stator earth-fault protection utilizes the differential principle, which provides high sensitivity and security. This ensures correct operation even during low load conditions.