Control Upgrades

Power Generation


Built in the mid-seventies, Navajo Generating Station is a three unit 2,250 megawatt coal-fired power plant located on the Navajo Nation in Arizona. NGS had retrofitted the original excitation systems with GE’s EX2000 Excitation systems beginning in 2003. The large exciters represent a significant investment, but the Salt River Project team sought to leverage the benefits of the latest digital control technology to meet its stringent reliability and operational goals, while minimizing cost and installation time.


GE worked with Salt River Project to lay out a plan to modernize the EX2000 control electronics while retaining the existing power converters, giving the NGS team the added function and continuing to leverage their prior investment. Ultimately, GE’s EX2100e Digital Front End (EX2100e DFE) was installed for the plant’s 750-MW Unit 2 at a fraction of the time and cost of a traditional excitation retrofit. Based on this successful installation, Salt River Project has plans to work with GE to upgrade its two additional 750-MW units within the next 12 months.


 A dependable, high-performance excitation control system is a key component of successful power plant operation. By partnering with GE, the plant upgraded to the industry’s most advanced excitation system at a fraction of the time and cost of a traditional excitation retrofit.

*The first of its kind, this project represents the first installation of GE’s L-Frame EX2100e Digital Front End (EX2100e DFE). Guided by GE’s expert team of dedicated engineers, the upgrade was completed within the scheduled 10-day outage plan.

*The EX2100e DFE provides the latest control features without the need to disturb the AC or DC power connections to the exciter, and GE’s flexible communications architecture enables connectivity with the plant’s other control systems.

*GE’s dedicated retrofit specialists also provided the plant with a custom migration design package, including site engineering, installation, and commissioning services to ensure a high quality installation and startup.


The plant has experienced the following benefits as a result of this modern control system upgrade project:

*Improved security, reliability, and availability

*Reduced outage duration and upgrade costs through pre-engineered EX2100e DFE packages

*Greater data availability through improved hardware and software Toolbox functionality

*Enhanced operational modes and alarm management

*Increased availability of spare parts and better protective functions

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