Control system combines off-the-shelf components with Terminator I/O for complex turbine generator applications
Ernesto Colon
Vice President and Start Up/Controls Engineer for TDS
__________________________________________
Turbine Diagnostic Services (TDS) is a power generation field service company that provides industrial, utility, IPP, and municipality power generation systems for turbine generator applications. The company's TurboNet DASH 1 ® Control System is a complete DCS-structured Turbine Generator Control System designed and produced by the company. The company developed the system to meet the needs of customers looking for a stable, "crash-free" system for turbine control applications. "Our Linux and LYNX OS operating platforms make our system much more stable than Windows-based systems, and offers a reliable, real-time operating environment," says John Todd, TurboNet Programmer for TDS.
The system includes a complete control panel, an HMI (Human Machine Interface) station, an optional EWS (Engineering Work Station), and Historian systems, all designed and packaged by TDS to effectively balance plant and turbine controls in one cost-effective package. The system is easily adaptable to various size steam, mechanical drive, and gas turbine control applications, and, because of its compact design, is also perfect for retrofits and upgrades and offers flexible installation. " The TurboNet HMI and EWS, Monitors and Historian software can be installed on our standard hardware platform or the customer's dedicated control room hardware platform to match other components utilized by the customer, says Ron Rubrecht, President.
The TurboNet DASH 1 Control System hardware architecture includes off-the-shelf, readily available computer components, with the exception of three specialized I/O modules, to reduce the cost of ownership and maintenance. The power supplies used are available in a redundant configuration using industry standard components, both the control panel and HMI station are based on industry standard, x86 compatible microprocessors, and all monitors are industry standard LCD displays. "The off the shelf price of our components makes the TurboNet extremely cost effective. The customer can afford to have a complete set of spare parts in stock for a price similar to that of other system individual component pricing," explains Brian Walsh, Senior Designer for TDS.
TDS also uses the Terminator I/O line of input/output modules from AutomationDirect, and has developed a protocol to communicate without redundant control processors via the Terminator I/O's Ethernet-based network interface. TDS uses all of the standard I/O modules of the Terminator line and has developed low-density termination boards that interface with the terminal base wiring to the I/O module. These termination boards provide suppression and fuse protection to the I/O as required, and standard contact relay outputs operated by the Terminator I/O output modules. The termination boards also offer special features to supply power to wet outputs through internal system voltages with jumpers located on the cards. Using a minimum of three nodes of Terminator I/O modules, each individually powered and with separate Ethernet network interfaces, the TurboNet DASH 1 control system is able to handle triple redundant field I/O. The Terminator I/O modules are hot-swap modules, which allow non-critical I/O or redundant critical I/O to be changed online.
The control system scans the I/O and performs all the control processing at a 20ms scan rate. The "hot standby" processor monitors the broadcast of the primary processor every 20ms and takes over control after two failed primary broadcasts in 50ms, allowing it to be in service on the third scan. The control processors interface with the HMI via the main data highway to provide data for monitoring and alarming, and to receive data regarding operator initiated control commands. Alarms are generated and annunciated visually and audibly in four levels of alarm importance.
In order to handle the complexity of turbine generator control, TDS has developed three specialized I/O modules in cooperation with AutomationDirect that seamlessly interface into the standard Terminator I/O terminal bases and Ethernet network interfaces. These three specialized I/O modules (an overspeed module, servo loop control module and a vibration module) are used for the control and protection of the turbine generator interfacing with device applications typical of turbine generator industry standards.
The TurboNet DASH 1 control system can be monitored and troubleshot from remote locations via a high-speed Internet connection. Remote programming changes can be made and implemented online. The system can be operated remotely and access any of the historical data collected. It is also easily expanded to control multiple units or the entire site on the same data highway, from one or many control points as required.
Author bio:
Ernesto Colon is the Vice President and Start Up/Controls Engineer for TDS. Colon designed and wrote the code for the TurboNet Dash 1 control system. His experience includes time as a Field Engineer for GE. He is a Graduate of Purdue with a B.S.M.E. For more information on TDS and the TurboNet DASH 1 control system, visit the company's Web site at http://www.turbinedoctor.com.
__________________________________________________________________
Links to the current issue of Automation Notebook are found below.
Click the Back Issues link to visit the archives.
Back to Application Stories
