Santee Cooper modernizes Winyah Station with digital control system

Located between Myrtle Beach and Charleston, South Carolina’s Santee Cooper Winyah Generating Station has been working with GE Energy to modernize and upgrade their Westinghouse Control System with GE’s most advanced digital control system for turbines, the Mark VIe Triple Modular Redundant (TMR).

Santee Cooper is South Carolina's state-owned electric and water utility and is the largest power provider in the state. It utilizes a diverse fuel and energy supply of coal, nuclear, oil, gas, hydro and renewables to directly serve more than 165,000 residential and commercial customers in Berkeley, Georgetown and Horry counties. Santee Cooper also supplies power indirectly to all 46 counties of the state (through wholesale customers).

When it was built, Winyah was Santee Cooper's most ambitious generating project. Units 3 and 4 at this site were the first in the Southeast to have "scrubbers," which help hold down emissions into the environment.

This spring, the existing Westinghouse EHC control system on the Winyah plant’s Unit No. 4 steam turbine generator will be migrated to a Mark VIe TMR control system. This is the first Mark VIe Control System to replace an existing Westinghouse Control System, although GE has been working to modernize other systems at Santee Cooper, including the June 9, 2010 replacement of a Mark II with a Mark VI at Cross Station.

The Mark VIe TMR is a custom-programmed, expandable, digital control system. It will be mounted and prewired in new cabinetry, then installed. The Mark VIe TMR is the latest turbine control system from GE's Control Solutions business. It provides modules for interfacing with nearly every type of sensor on the market today.

The Mark VIe TMR modernization will extend the life of the Winyah plant and improve the equipment reliability, reducing downtime and expensive maintenance. The Mark VIe TMR also provides Santee Cooper the opportunity to improve their existing turbine control with the addition of modern instrumentation as well as more robust and precise control of the equipment.

The base scope of the Westinghouse conversion includes a Mark VIe TMR Cabinet, 2 HMIs with 4 network switches, a primary emergency overspeed kit, Watt/VAR transducer, a factory acceptance test, on-site training, and on-site technical direction.

Benefits of the Mark VIe TMR digital control:

• Reduced maintenance, costs, and downtime
• Increased mean time between failures (MTBF)
• Modern maintenance tools and diagnostics for troubleshooting in real-time
• Remote monitoring capability to reduce time spent manually monitoring