Greater Des Moines Energy Center Combined Cycle Plant

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Greater Des Moines Energy Center Combined Cycle Plant Diagram of a Combined Cycle Generator Solve for Monotonically Increasing Units Load User Defined Inputs Combine Solution Sets Output Optimal Dispatch Solve for Non-Monotonically Increasing Units Other Resources None required Faculty Advisor Dr. John Lamont jwlamont@iastate.edu Economic Dispatch of Non-Monotonically Increasing Generators May 06-07 Abstract Combined-cycle generating units are being incorporated into the current power systems in order to meet peak loading contingencies as efficiently as possible.  Combined-cycle generating units consist of two simple-cycle combustion turbines and one heat-recovery steam generator. Combined-cycle generating units exhibit non-monotonically increasing cost curves which cannot be solved by classical economic dispatch optimization methods. The project team is modifying and redesigning a pre-existing algorithm to calculate optimal economic dispatch, including both monotonically and non-monotonically increasing generators, with a shorter solution time. Major milestones include comprehension of the pre-existing optimization algorithms, implementation of the algorithms in Microsoft Excel using Visual Basic macro programming, redesign of the optimization algorithm for faster solution speed, and delivery of the software and documentation to the client.  Optimal results will allow for power to be produced at the lowest possible cost to the client while prolonging the life of each generating unit. Introduction • Project Requirements • Problem Statement • General Problem Statement • Conventional monotonically increasing algorithms will not dispatch non-monotonically increasing units without altering the data, thus currently an optimal solution can not be found. • General Problem Solution • Modification of a pre-existing algorithm incorporated into Microsoft Excel macros in order to give MidAmerican Energy the lowest cost solution to meet their power demand with the shortest solution time possible. • The project team will focus their concentration on improving the structure of the unit commitment page, reorganizing the way output is displayed, implementing a main menu, and finally restructuring the code to allow the user to dispatch only a range of hours. • Operating Environment • Use Visual Basic macro programming embedded in the form of a Microsoft Excel workbook • The software will run on a windows-based system with adequate processing capabilities • User • MidAmerican generation dispatchers • MidAmerican short-term energy traders • Uses • Optimize the economic dispatch of monotonically increasing and non-monotonically increasing generators • Benchmark cost curves for future algorithm designs • Assumptions • Enumeration / iteration will be used as the optimization method for the algorithm • 12 monotonically increasing units and 2 sets of non-monotonically increasing units are being modeled • Limitations • Software shall use Microsoft Excel as the interface • Input data for generating units shall use piece-wise linear incremental cost curves • Results must be written into a single Excel workbook • Expected End-Product • Excel workbook file with Visual Basic macros • User instructions documentation • Easy to use interface • Design Objectives • Flexible program design • Well-commented program code • Comprehensive iteration scheme • Functional Requirements • Provide best generator dispatch • Output iteration calculations • Design Constraints • Five-minute limit on iteration run time • Expandable for future additional generating units • Clear box design enabling modifications of program • The software shall utilize Microsoft Excel as the interface • Measurable Milestones • End-product Design Dec. 08, 2005 • Product prototype Jan. 23, 2006 • Product testing Mar. 23, 2006 • Product documentation Apr. 10, 2006 • Product demonstration Apr. 26, 2006 Resources and Schedule Project Schedule Gantt Chart Financial Requirements/Personnel Effort Proposed Approach • Proposed Approach • Technologies Considered: • Visual Basic (required by client) • Microsoft Excel (required by client) • Testing Considerations: • Test the algorithm using Matlab Linear Programming • Client testing in client’s environment Block diagram of proposed program Closing Summary The project will build upon a software application that will seek to produce the most economical power generation, with as quick of solution times as possible, between monotonically and non-monotonically increasing generators. The algorithm will be able to handle more generator combinations and will be combined with a more aesthetically pleasing user interface to produce a more usable application. This program will be written in Microsoft Excel using Visual Basic macros and will meet the many outlined requirements. MidAmerican Energy can expect to benefit from this project through a reduction in fuel costs due to improved generator operation. Team Members Client Matthew Ellis EE mjellis@iastate.edu Noraima Fernandez EE fernandl@iastate.edu Jeremy Hamilton EE jerbud@iastate.edu Robert Walter EE rmwalter@iastate.edu Alan Oneal aroneal@midamerican.com Webpage http://seniord.ee.iastate.edu/may0607/ References: Pictures from midamericanenergy.com and energyquest.ca.gov