Optimization of Scheduling for Hydro-thermal Power Generation and Transmission Including Pumped Storage Systems

This work presents a novel approach for solving the short-term scheduling of hydro-thermal power generation, including pumped storage systems and transmission constraints. The problem addressed is known as Security Constrained Unit Commitment (SCUC). Pumped Storage Units (PSUs) are important in electric systems during the off-peak and the peak demand periods, providing economic and technical benefits. Linear aproximations are applied to nonlinear equations of this kind of mathematical problems which are: fuel cost functions, generation-discharge curves of PSUs and transmission constraints modeled with Alternating Current power flow model. Thus, MILP models are presented for the problem addessed. To prove the efficiency of the proposed models, two systems with PSUs will be tested: a modified 6-bus and the IEEE 31-bus power system. Results show that the proposed MILP models allow: modeling the SCUC problem more realistically, obtaining feasible solutions within efficient computational times, and reaching production cost savings up to almost 15% compared to power systems that lack capacities to pumping water. Several indicators obtained from results are presented through graphs, as a tool for improving operation and maintenance of power systems. The analysis of these indicators and the graphic interpretation allow to identify and classify critical parts of systems as well as to make recommendations about future system improvements.Sociedad Argentina de Informática e Investigación Operativ

Optimization of Scheduling for Hydro-thermal Power Generation and Transmission Including Pumped Storage Systems

This work presents a novel approach for solving the short-term scheduling of hydro-thermal power generation, including pumped storage systems and transmission constraints. The problem addressed is known as Security Constrained Unit Commitment (SCUC). Pumped Storage Units (PSUs) are important in electric systems during the off-peak and the peak demand periods, providing economic and technical benefits. Linear aproximations are applied to nonlinear equations of this kind of mathematical problems which are: fuel cost functions, generation-discharge curves of PSUs and transmission constraints modeled with Alternating Current power flow model. Thus, MILP models are presented for the problem addessed. To prove the efficiency of the proposed models, two systems with PSUs will be tested: a modified 6-bus and the IEEE 31-bus power system. Results show that the proposed MILP models allow: modeling the SCUC problem more realistically, obtaining feasible solutions within efficient computational times, and reaching production cost savings up to almost 15% compared to power systems that lack capacities to pumping water. Several indicators obtained from results are presented through graphs, as a tool for improving operation and maintenance of power systems. The analysis of these indicators and the graphic interpretation allow to identify and classify critical parts of systems as well as to make recommendations about future system improvements.Sociedad Argentina de Informática e Investigación Operativ

Optimización en tiempo real con disyunciones lógicas: aplicación a sistemas de calor y potencia

La optimización en tiempo real (RTO) permite operar en cercanías del óptimo económico de una planta, respetando restricciones y respondiendo a cambios en el proceso. La adaptación con términos modificadores de las restricciones y los gradientes corrige eficientemente los errores estructurales de los modelos de RTO. Este trabajo propone el uso de RTO incluyendo disyunciones lógicas en el problema de optimización, y plantea una estrategia de adaptación con modificadores para este problema. La estrategia se muestra a través de un caso de estudio que consiste en un sistema de generación de vapor y potencia. Los resultados obtenidos muestran la validez de la estrategia sugerida y la utilidad de incluir variables discretas o disyunciones en los sistemas de RTO.Sociedad Argentina de Informática e Investigación Operativ

Optimization of Scheduling for Hydro-thermal Power Generation and Transmission Including Pumped Storage Systems

This work presents a novel approach for solving the short-term scheduling of hydro-thermal power generation, including pumped storage systems and transmission constraints. The problem addressed is known as Security Constrained Unit Commitment (SCUC). Pumped Storage Units (PSUs) are important in electric systems during the off-peak and the peak demand periods, providing economic and technical benefits. Linear aproximations are applied to nonlinear equations of this kind of mathematical problems which are: fuel cost functions, generation-discharge curves of PSUs and transmission constraints modeled with Alternating Current power flow model. Thus, MILP models are presented for the problem addessed. To prove the efficiency of the proposed models, two systems with PSUs will be tested: a modified 6-bus and the IEEE 31-bus power system. Results show that the proposed MILP models allow: modeling the SCUC problem more realistically, obtaining feasible solutions within efficient computational times, and reaching production cost savings up to almost 15% compared to power systems that lack capacities to pumping water. Several indicators obtained from results are presented through graphs, as a tool for improving operation and maintenance of power systems. The analysis of these indicators and the graphic interpretation allow to identify and classify critical parts of systems as well as to make recommendations about future system improvements.Sociedad Argentina de Informática e Investigación Operativ

Optimización en tiempo real con disyunciones lógicas: aplicación a sistemas de calor y potencia

La optimización en tiempo real (RTO) permite operar en cercanías del óptimo económico de una planta, respetando restricciones y respondiendo a cambios en el proceso. La adaptación con términos modificadores de las restricciones y los gradientes corrige eficientemente los errores estructurales de los modelos de RTO. Este trabajo propone el uso de RTO incluyendo disyunciones lógicas en el problema de optimización, y plantea una estrategia de adaptación con modificadores para este problema. La estrategia se muestra a través de un caso de estudio que consiste en un sistema de generación de vapor y potencia. Los resultados obtenidos muestran la validez de la estrategia sugerida y la utilidad de incluir variables discretas o disyunciones en los sistemas de RTO.Sociedad Argentina de Informática e Investigación Operativ

Hydrothermal Unit Commitment with Deterministic Optimization : Generation and Transmission Including Pumped Storage Units

This work presents a novel approach for solving the short-therm scheduling of hydro-thermal power generation, including pumped storage systemsand transmission constraints. The problem addressed is known as Security Constrained Unit Commitment (SCUC). Pumped Storage Units (PSUs) are importantin electric systems during the off-peak and the peak demand periods, providing economic and technical benefits. Linear aproximations are applied to nonlinear equations of this kind of mathematical problems which are: fuel cost functions, generation-discharge curves of PSUs and transmission constraints modeled with Alternating Current power flow model. Thus, MILP models are presented for the problem addessed. To prove the efficiency of the proposed models, two systems with PSUs will be tested: a modified 6-bus and the IEEE 31-bus power system. Results show that the proposed MILP models allow: modeling the SCUC problem more realistically, obtaining feasible solutions within efficient computational times, and reaching production cost savings up to almost 20% compared to power systems that lack capacities to pumping water. Several indicators obtained from results are presented through graphs, as a tool for improving operation and maintenance of power systems. The analysis of these indicators and the graphic interpretation allow to identify and classify critical parts of systems as well as to make recommendations about future system improvements.Sociedad Argentina de Informática e Investigación Operativ

A decomposition method for synthesizing complex column configurations using tray-by-tray GDP models

This paper describes an optimization procedure for the synthesis of complex distillation configurations. A superstructure based on the Reversible Distillation Sequence Model (RDSM) is proposed embedding all possible alternative designs using tray-by-tray models. Generalized Disjunctive Programming (GDP) is used to model the superstructure. Due to the large size and complexity of the formulation, a decomposition solution strategy is proposed where discrete decisions are decomposed into two hierarchical levels within an iterative procedure. In the first level, the column sections are selected yielding a candidate configuration. In the second level, the feed location and the number of trays of the selected sections are optimized. A preprocessing phase including thermodynamic information is considered to provide a good starting point to the algorithm in order to improve the convergence and robustness of the method. Examples are presented for zeotropic and azeotropic multicomponent mixtures to illustrate the performance of the proposed method. Nontrivial configurations are obtained involving modest solution times. 1