OverviewGENERREX excitation systems were a high performance design for large steam-turbine generators installed from 1975 to 1995. The 49 installed systems consisted of two major design types but shared the use of three-phase water-cooled P-Bars, wound into the generator stator to provide excitation voltage. No external AC power source was required. The first generation compound power source (CPS) system was comprised of large excitation transformers and linear reactors mounted in the generator dome, a set of water-cooled rectifier bridges, and an analog voltage regulator. Later units were shipped as power potential source (PPS) systems. These units replaced the excitation transformers and linear reactors with a power potential transformer mounted in the generator dome or on the generator lagging, fed by the P-Bars. Control PlatformReasons to UpgradeCurrent issues with these systems are typical of any aging control system with a limited installed base, including: parts availability, service availability, increased maintenance, and limited data access for operations and maintenance. Application-specific issues include: water leaks in the power bridges, failure modes, and repair support for the critical dome mounted magnetics. Product DescriptionThe EX2100 is available for GENERREX applications in a redundant (multi-bridge) configuration with ratings up to 1,300Vac and 7,700A. It includes conversion of the CPS or PPS system to a potential source system supplied from the generator terminals or station auxiliary bus. P-Bars are no longer needed for excitation voltage and are disabled in place within the generator. If the retrofit is combined with a generator rewind, the P-Bars can be removed, reducing the cost of the rewind. Other options include new software functions, operator stations, power system studies, and remote monitoring & diagnostics.ValueBy working with GE's generator engineering and services teams, customers can be assured that the required generator dome and P-bar modifications are designed to reduce project risk and optimize generator performance. GENERREX retrofits improve reliability and reduce maintenance by helping to eliminate water leaks, regulator alignment, and thermal drift, and by providing access to readily available spare parts and expert service resources. GE's engineered retrofit of the GENERREX system can deliver all of the design and implementation support needed to retain the performance benefits of the original system, while integrating the new EX2100 systems into the existing plant infrastructure. |
Related Links |
|
GENERREX™ Excitation System Retrofits
|