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

Problema de asignación de aulas en universidades: un enfoque basado en programación de metas

En este trabajo se aborda el problema de asignación de aulas en universidades, que consiste en un problema particular de asignación de recursos limitados persiguiendo un cierto objetivo. El problema planteado por día puede formularse como: dado un conjunto de clases con sus respectivos horarios, cantidad de alumnos y requerimientos específicos, el objetivo es asignar un aula con capacidad suficiente a cada clase, satisfaciendo ciertos criterios de calidad para la asignación. Formulado como un problema de programación matemática, en muchos casos este problema resulta infactible. En consecuencia, se propone un abordaje basado en programación de metas, dividiendo las restricciones en restricciones duras y restricciones blandas. Se resuelve aplicando el método preventivo, a través de dos problemas de programación matemática del tipo mixto entero lineal. Se resuelven dos casos reales de aplicación, que permiten ilustrar la eficiencia de la metodología propuesta.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

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

Evaluación de modelos AC y DC para problemas de asignación de unidades generadoras incorporando restricciones de transmisión en sistemas eléctricos: formulaciones MILP y MINLP

En este trabajo se efectúa una evaluación y comparación de dos modelos para la resolución del problema de programación de unidades generadoras, para satisfacer la demanda eléctrica de un sistema con restricciones de transmisión en sus formatos de programación matemática. El modelo AC, caracterizado por su mayor complejidad da lugar a una formulación MINLP; y el modelo DC, que es una versión simplificada y su implementación produce una formulación MILP. Se describen los modelos que representan la generación de energía eléctrica en centrales térmicas con restricciones de transmisión. Se presentan conclusiones sobre los dos modelos en cuanto a los valores de sus funciones objetivo, tiempos de cómputo, y resultados del despacho económico. También se estudia la factibilidad de emplear las soluciones obtenidas con el modelo simplificado en el modelo más complejo.Sociedad Argentina de Informática e Investigación Operativa (SADIO

Evaluación de modelos AC y DC para problemas de asignación de unidades generadoras incorporando restricciones de transmisión en sistemas eléctricos: formulaciones MILP y MINLP

En este trabajo se efectúa una evaluación y comparación de dos modelos para la resolución del problema de programación de unidades generadoras, para satisfacer la demanda eléctrica de un sistema con restricciones de transmisión en sus formatos de programación matemática. El modelo AC, caracterizado por su mayor complejidad da lugar a una formulación MINLP; y el modelo DC, que es una versión simplificada y su implementación produce una formulación MILP. Se describen los modelos que representan la generación de energía eléctrica en centrales térmicas con restricciones de transmisión. Se presentan conclusiones sobre los dos modelos en cuanto a los valores de sus funciones objetivo, tiempos de cómputo, y resultados del despacho económico. También se estudia la factibilidad de emplear las soluciones obtenidas con el modelo simplificado en el modelo más complejo.Sociedad Argentina de Informática e Investigación Operativa (SADIO

Deterministic optimization of the thermal Unit Commitment problem: A Branch and Cut search

This paper proposes a novel deterministic optimization approach for the Unit Commitment (UC) problem, involving thermal generating units. A mathematical programming model is first presented, whichincludes all the basic constraints and a set of binary variables for the on/off status of each generator ateach time period, leading to a convex mixed-integer quadratic programming (MIQP) formulation. Then,an effective solution methodology based on valid integer cutting planes is proposed, and implementedthrough a Branch and Cut search for finding the global optimal solution. The application of the pro-posed approach is illustrated with several examples of different dimensions. Comparisons with other mathematical formulations are also presented