Broad River Dam: 3 control levels

Lockhart Power Co. owns and operates a hydroelectric plant located on the Broad River in upstate South Carolina, striving to be a low-cost energy provider for more than 6,000 direct customers and 6,000 indirect customers with a 90-mile transmission network. The utility considered its prior proprietary microprocessor-based control system obsolete in an industry undergoing deregulation and contin...

02/01/2008


Lockhart Power Co. owns and operates a hydroelectric plant located on the Broad River in upstate South Carolina, striving to be a low-cost energy provider for more than 6,000 direct customers and 6,000 indirect customers with a 90-mile transmission network. The utility considered its prior proprietary microprocessor-based control system obsolete in an industry undergoing deregulation and continuing competitive pressures.

The plant’s eight-gate dam feeds a canal that channels water to the powerhouse. The powerhouse contains five turbine generators with a combined power capacity of over 17 MW. The dam and turbine control system receive data from power, flow, and level sensing devices to perform monitoring and control of the dam, generators, and associated equipment.

Lockhart required a control system providing open networking capabilities, and a lower total cost of ownership. The new system needed to coexist with an upgraded design of existing hardwired generator controls, and perform distributed, independent control at the dam and each of the five turbine stations.

Lockhart Power contracted North Fork Electric in Crumpler, NC, a provider of hydroelectric products and systems integration services, to implement the renovation. North Fork Electric proposed a three-tier solution. Level 1 includes new hardwired controls for manual operation of the system. Level 2 includes PLC-based control of the dam and generators in an automatic mode. Level 3 provides PC-based redundant control and monitoring from a central location connected to the plant-wide Ethernet network.

The system uses seven AutomationDirect DirectLogic DL205 micro-modular PLCs with D2-250 CPUs that have PID functionality. Each of the five systems for generator control includes I/O modules for digital and analog I/O, and an Ethernet communications module. The remaining two PLCs are configured in a master/slave arrangement and control the dam gates—located upriver from the powerhouse—via radio modems. Low-cost Ethernet connections for the PLCs also helped.

To reduce maintenance costs, North Fork Electric selected matching I/O components to maximize commonality among systems. The identical analog output modules used on the generators, configured for

To complete Level 2 control, North Fork Electric installed the dam control system. The system controls eight canal gates at the dam, which regulate the flow of water downstream to the turbines. The operator enters the required gate-position setpoints using a second color touch panel connected to the dam control’s master PLC in the control room. Data is transmitted to the slave PLC, located at the dam, via a 900 MHz radio modem. The slave PLC monitors gate positions using proximity switches that count teeth on the drives’ gears and move the gates.

The third tier of control and monitoring uses the LookoutDirect SCADA system, which communicates to the PLCs over an Ethernet network. This SCADA system performs supervisory control and collects data for the plant’s information system.

Edited by Control Engineering with information from AutomationDirect and North Fork Electric.





No comments
The Engineers' Choice Awards highlight some of the best new control, instrumentation and automation products as chosen by...
Each year, a panel of Control Engineering editors and industry expert judges select the System Integrator of the Year Award winners.
Control Engineering Leaders Under 40 identifies and gives recognition to young engineers who...
Learn more about methods used to ensure that the integration between the safety system and the process control...
Adding industrial toughness and reliability to Ethernet eGuide
Technological advances like multiple-in-multiple-out (MIMO) transmitting and receiving
Virtualization advice: 4 ways splitting servers can help manufacturing; Efficient motion controls; Fill the brain drain; Learn from the HART Plant of the Year
Two sides to process safety: Combining human and technical factors in your program; Preparing HMI graphics for migrations; Mechatronics and safety; Engineers' Choice Awards
Detecting security breaches: Forensic invenstigations depend on knowing your networks inside and out; Wireless workers; Opening robotic control; Product exclusive: Robust encoders
The Ask Control Engineering blog covers all aspects of automation, including motors, drives, sensors, motion control, machine control, and embedded systems.
Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
News and comments from Control Engineering process industries editor, Peter Welander.
IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.
This is a blog from the trenches – written by engineers who are implementing and upgrading control systems every day across every industry.
Anthony Baker is a fictitious aggregation of experts from Callisto Integration, providing manufacturing consulting and systems integration.
Integrator Guide

Integrator Guide

Search the online Automation Integrator Guide
 

Create New Listing

Visit the System Integrators page to view past winners of Control Engineering's System Integrator of the Year Award and learn how to enter the competition. You will also find more information on system integrators and Control System Integrators Association.

Case Study Database

Case Study Database

Get more exposure for your case study by uploading it to the Control Engineering case study database, where end-users can identify relevant solutions and explore what the experts are doing to effectively implement a variety of technology and productivity related projects.

These case studies provide examples of how knowledgeable solution providers have used technology, processes and people to create effective and successful implementations in real-world situations. Case studies can be completed by filling out a simple online form where you can outline the project title, abstract, and full story in 1500 words or less; upload photos, videos and a logo.

Click here to visit the Case Study Database and upload your case study.