Our community spends most of its time designing, applying, or using automation and control systems.  This session provides descriptions of systems, programs, and projects, emphasizing experiences and lessons learned during conceptual and application engineering, design, fabrication, installation, startup, operation, and/or maintenance activities

 

 

P002-”Intelligent Process for On-Line Optimal Load Distribution Between Units In A Hydro Power Plant”

Edson Bortoni, Unifei - Federal University of Itajubá

 

The sustainable development and the reasonable exploitation of natural energy resources are key issues and have becoming one of the greatest challenges of XXI century. Hydro power plants are in the hurricane eye as long as they deal with these two sides of the coin. In the case of Brazil, where hydro accounts with about 75% of the total power generation, every tenth of percent increasing in the energy conversion efficiency is well received. A less expensive way to reach this objective is to make an optimal operation of the existent units of power plant. In general, the total amount of generation is dispatched from an operation center. Nevertheless, the distribution between the existent machines is a local decision. This paper proposes an optimization method for real time optimal load allocation between units in a hydroelectric power plant. The objective is maximizing the efficiency of hydro to electrical energy conversion.  An optimization algorithm is developed based on the “Steepest-Ascent Hill Climbing” heuristic. The paper also discusses about the necessary instrumentation and makes a review of optimal operation schemes. The developed methodology is applied a hypothetical and to a real power plant

 

 

P007-”Virtual Instrumentation In Monitoring and Control Interface of a Wind Turbines Park

Luis Lopez-Manrique, MS, Universidad Juárez Autónoma de Tabasco

 

We have developed to an interface for monitoring and control of a park of wind turbines in which it is possible to make the statistics of production and generation of electrical energy, detection of errors of faults, as well as the control of the operation and the maintenance.  This interface is in the second phase of improvement and development. The second version is working with virtual instruments and a special programming language. The first version developed the communication protocol to work in a network by optical fiber and a remote connection of via radio to a distance of 25 miles.

 

 

P015-”Control Room Design - Lessons Learned”

Richard Marshall, Kansas City Power & Light; Jon Shadduck, AmerenUE

 

A control system retrofit project provides an opportunity to rethink an existing control room area to create a functional, secure, and comfortable operating environment.  Upgrades to lighting, HVAC, flooring and ceiling treatments are a relatively small portion of the overall project budget but they can have a substantial impact on the perceived success of a control retrofit project.

 

Plant staff who have spent many years occupying an existing control space have valuable, insightful suggestions for improving a control room area to best fit their needs.  Their input coupled with the latest architectural design practices has led to many valuable lessons during the course of dozens of fossil plant controls upgrade projects. Issues addressed in this paper include the following:

·         Floor plan design for traffic control and work area adjacencies

·         Lighting design

·         Emerging trends in large format displays

·         Workstation furniture alternatives

·         Flooring and ceiling materials

·         Dust mitigation

·         Noise abatement

 

 

P019-”Automated Power Management Systems for Power Consumers with On-site Generation”

Scott Manson, Shah Saurabh, Schweitzer Engineering Laboratories

 

Co-located generation capabilities are finding great popularity among Industrial, Commercial, Retail, and Governmental power consumers.  These are being installed for economic, safety, and environmental reasons. For example, an oil refinery may install on-site generation to reduce their unit electric energy costs, to enable their plant to continue operations during local utility outages, to reduce environmental emissions by reducing the number of plant outages, and subsequently to improve personnel safety through fewer ‘emergency’ shutdowns. As the number of individual unit generators increases, so does the need for more powerful methods by which to monitor, control, and optimize the operation of the generation and the load throughout their facilities.  In the last decade, powerful microprocessor controlled protection, automation, and communication devices have become available, which greatly simplify the task of automation and management of these ‘mini’ power systems.  In addition to greatly enhanced features, these modern devices have made electric power more reliable and more economical than ever before.  This presentation reviews a recently installed Automated Power Management System, that provided the customer with a simple and robust system architecture of the highest quality and cost-effectiveness.  This customer is a very large oil refinery in Europe. The automated elements of this system that will be discussed include:  High-speed Automatic Load Shedding, Automatic Generation Control (AGC) and Dispatch, System Frequency Control, Automatic MVAR Control and Dispatch, System Voltage regulation, Automatic System Islanding detection, and Governor Mode Control.  Automatic System Separation and Load Restoration are other great items worthy of discussion that have been provided to other similar customers. The fundamental diagnostic, engineering, and maintenance features of this system that will be discussed include: a fully redundant-server-based data acquisition and monitoring system using OPC for 45,000 tag updates per second, high speed TCP-based Ethernet Communications used for 70,000 tags updates per second, a microprocessor-based protective relaying system, a quad-redundant substation-hardened Ethernet switching communication architecture, power quality monitoring, serial and Ethernet communications processing, substation hardened computing platforms (with IEC 6-1131 programming), high speed UDP-based Ethernet Communications used for peer-to-peer communications, digital fault recording (oscillography), fault data analysis software, sequence of events recording (SER), SER data sorting and analysis software, protective relay settings management software, remote VPN administrative access, and satellite-based time synchronization of all electronic devices in the customer’s power system.

 

 

P022-”Control Strategies and Implementation for NH3 Vaporization”

Mac Buzanowski, Peerless Manufacturing Co.

Several commercially developed processes are available for NOx control at power plants. One of the most efficient technologies is the Selective Catalytic Reduction (SCR) process that is capable of over 95% reduction of NOx emissions. This technology is generally considered as a Best Available Control Technology (BACT) that represents the most stringent NOx emissions control process to be technologically feasible and cost effective. The SCR system requires injection of ammonia (NH3) into a NOx-laden exhaust gas stream.  The source of ammonia can be anhydrous ammonia, aqueous ammonia or urea.

A control strategy available to vaporize and dilute aqueous ammonia is described and its success is demonstrated in a recent SCR project. In this project, heated air is used as the dilution and evaporation medium. A multi-stage electrical flanged heating element is used to heat the ambient air. This heating element is inserted into the vaporizer and sealed onto the heater element flange.

An automatic control system is used to ensure complete ammonia evaporation within the vaporizer. This control system governs the transient amount of heat release by the heating element to maintain a specific temperature of the diluted ammonia at the outlet of the vaporizer. The heat release is function of several factors:

·         Ambient air temperature

·         Flow rate of ammonia into the vaporizer

·         Surface temperature of the heating element limited to avoid excessive heating that can damage the element

·         Hot air temperature at the bottom of the vaporizer

 

This paper presents heat balance simulations to determine the required heater element capacity. Detailed simulations are also presented to evaluate the evaporation of aqueous ammonia in the vaporizer. The control strategy used to ensure complete evaporation and protection from thermal damage is discussed.

 

 

P036-”Draft Control Enhancement on TAEAN Thermal Power Plant Units 1-4”

In-young Jeong. Korea Western Power Co., Ltd. (WP) Western Power

 

Taean thermal power plants are supercritical once-through coal fired 500Mw thermal power plant that adopts    balanced draft system. Draft systems consisted of FDF, IDF are operated hydraulically to control air flow using variable pitch blade. The control unit is equipped with thyristor reversing unit. We experienced lots of trouble, runback and plant trip because of fan actuator. So we have several significant logic modifications that were executed to improve draft control reliabilities.

1.        We add FDF, IDF control deviation high alarm, actuator power off logic to prevent shutdown by way of abrupt pitch blade closing or opening as a consequence of actuator faulty operation. These improvements allow the operator to detect faulty operation in early stages, take follow-up measures, and prevent plant shutdown.

2.        We change IDF feedforward signal from FDF Position signal to FDF demand signal to increase control stability, and we remove FDF, IDF position feedback control for lack of healthy feedback signal. As a result of this improvement, air flow and furnace pressure control is remarkably improved.

3.       We add FDF blocking interlock and change IDF blocking interlock from the front stage of feedforward signal to the final stage of control signal to prevent implosion protection and adverse action.

 

P057-“ Muskogee 4 Bottom Ash, Fly Ash and Pyrites Removal Controls Replacement and Consolidation”

Paul D. Lucy and Randall L. Miller, OG&E

 

OG+E’s Muskogee Generating Station is located along the east bank of the Arkansas River, approximately three miles east of Muskogee, Oklahoma.  The station consists of three large coal fired units and one smaller gas fired unit.  The three large coal fired units are rated at approximately 500 megawatts each, with a coal consumption rate of 300 tons/hour each at rated load.  The boilers on all three coal units are Combustion Engineering Tangential fired type with 6 firing elevations of which only 5 are required to meet rated load.  Powder River Basin (PRB) coal is delivered to the plant via train and is unloaded to the coal storage/reclaim area using a single rotary type dumper.

The new control system was deemed a success for a number of reasons.  Operation of the Fly Ash system is now more efficient because it only cycles on a hopper that is dumping ash into the system.  The Bottom Ash system is much more flexible with much more diagnostics and has yet to cause a line to plug.  The overall system has a great deal of diagnostics displayed on the PanelViews aiding operations ability to run the system and aiding the technician’s ability to maintain the system.  The prints are now all correct enabling much easier trouble shooting of the system.  With all of the new equipment and a very well programmed system, fault recovery time is fractional.  All of above mentioned items have made operating the Ash systems for Unit 4 more flexible and reliable.