Juan Pérez-Ruiz | Universidad de Málaga (original) (raw)
Papers by Juan Pérez-Ruiz
Renewable energy & power quality journal, Apr 1, 2017
IEEE Transactions on Power Systems, 2007
This paper analyzes the behavior of Hong's point estimate methods to account for uncertainties on... more This paper analyzes the behavior of Hong's point estimate methods to account for uncertainties on the probabilistic power flow problem. This uncertainty may arise from different sources as load demand or generation unit outages. Point estimate methods constitute a remarkable tool to handle stochastic power system problems because good results can be achieved by using the same routines as those corresponding to deterministic problems, while keeping low the computational burden. In previous works related to power systems, only the two-point estimate method has been considered. In this paper, four different Hong's point estimate schemes are presented and tested on the probabilistic power flow problem. Binomial and normal distributions are used to model input random variables. Results for two different case studies, based on the IEEE 14-bus and IEEE 118-bus test systems, respectively, are presented and compared against those obtained from the Monte Carlo simulation. Particularly, this paper shows that the use of the 2m + 1 scheme provides the best performance when a high number of random variables, both continuous and discrete, are considered.
2013 IEEE Grenoble Conference, 2013
This paper presents an algorithm to solve a unit commitment problem that takes into account the u... more This paper presents an algorithm to solve a unit commitment problem that takes into account the uncertainty in the demand. This uncertainty is included in the optimization problem as a joint chance constraint that bounds the minimum value of the probability to jointly meet the deterministic power balance constraints. The demand is modeled as a multivariate, normally distributed, random variable and the correlation among different time periods is also considered. A deterministic mixed integer programming problem is sequentially solved until it converges to the solution of the chance-constrained optimization problem. Different approaches are presented to update the z-value used to transform the joint chance constraint into a set of deterministic constraints. Results from a realistic size case study are presented and the values obtained for the multivariate normal distribution probability are compared with the ones obtained by using a Monte Carlo simulation procedure.
This paper presents a model to assess the value of power injection from residential installations... more This paper presents a model to assess the value of power injection from residential installations, with photovoltaic (PV) generation and/or electric storage, to the main grid. This model is posed as a multi-period two-stage stochastic economic dispatch, including ramping constraints and operating reserves, from the point of view of a central operator. Two sources of uncertainty are distinguished and represented as mid- and short-term scenarios: mid-term variability along the year and short-term forecasting errors. A case study, based on the Spanish power system, is presented to show the value of injection on both the operation costs and CO2 emissions. Results obtained allow us to provide some recommendations on the deployment of these residential installations.
Energies, 2021
This paper presents a robust optimization model to find out the day-ahead energy and reserve to b... more This paper presents a robust optimization model to find out the day-ahead energy and reserve to be scheduled by an electric vehicle (EV) aggregator. Energy can be purchased from, and injected to, the distribution network, while upward and downward reserves can be also provided by the EV aggregator. Although it is an economically driven model, the focus of this work relies on the actual availability of the scheduled reserves in a future real-time. To this end, two main features stand out: on one hand, the uncertainty regarding the EV driven pattern is modeled through a robust approach and, on the other hand, a set of non-anticipativity constraints are included to prevent from unavailable future states. The proposed model is posed as a mixed-integer robust linear problem in which binary variables are used to consider the charging, discharging or idle status of the EV aggregator. Results over a 24-h case study show the capability of the proposed model.
2021 IEEE PES Innovative Smart Grid Technologies Conference - Latin America (ISGT Latin America), 2021
Optimal sizing and operation of a household with photovoltaic (PV) and storage requires a proper ... more Optimal sizing and operation of a household with photovoltaic (PV) and storage requires a proper consideration of some uncertain parameters, as demand and PV generation. A one-year case study, including several scenarios and hourly discretization, may be very efficiently solved using an off-the-shelf solver on a laptop. However, getting those data is not always an easy task. In this work, we study whether it would be possible to get an approximate solution by using aggregate measures for those uncertain parameters and how should the problem be transformed to handle that aggregated information. By taking into account the average values of consecutive periods, we propose a linear transformation of the constraints and a set of additional ones to get this goal. Results over a case study show that the proposed procedure provides reasonable values, although the precision could be improved if some additional information, apart from the average values of the uncertain input data, is considered.
2019 IEEE PES Innovative Smart Grid Technologies Europe (ISGT-Europe), Sep 1, 2019
IET Renewable Power Generation, 2019
This study presents a model to analyse the effect of an increasing level of residential and comme... more This study presents a model to analyse the effect of an increasing level of residential and commercial photovoltaic and storage devices, intended for self-consumption, on a power system. A whole year is focused and modelled through a set of selected representative days. A 24-h two-stage stochastic unit commitment is solved for each representative day and expected results are weighted to achieve annual expected results. This optimisation problem includes appropriate representation of the day-ahead and on-line operations and an adequate representation of the uncertainty associated with renewable sources and demand. The main contributions are: (i) the definition of a single model in which customers are price-makers and large-scale and customers’ installations are appropriately modelled, therefore bridging the current macroscopic and microscopic modelling approaches, and (ii) the division of customers into four non-overlapping groups, which allows a sensitivity analysis of the effect of each group. Five main results are focused: net demand, CO2 emissions, load factors, system operation cost, and customer savings. The model is applied to a case study based on the Spanish power system to show the model capability to quantify the effect of an increasing level of these promising technologies on a power system.
En esta tesis se desarrolla un modelo de costes de produccion multiperiodo para un sistema de ene... more En esta tesis se desarrolla un modelo de costes de produccion multiperiodo para un sistema de energia electrica, Este modelo integra la tecnica de simulacion probalista con la optimizacion en un problema de programacion lineal.Este problema, que inicialmente tiene estructura de plimatroide, puede incluir cualquier tipo de resticcion de despacho que pueda ser fomulada como una funcion lineal de los valores esperados de energia. La dimension del citado problema de optimziacion excede con creces la capacidad de los paquetes comerciales de optimizacion. En esta tesis se desarrollan dos metodos de resolucion alternativos altamente eficientes. El primero de ellos es una estrategia activa aplicada al metodo simples y el segundo se basa en la aplicacion de la tecnica de descomposicion de Dantizg-Wolfe. Ambos metodos se aplican a un caso de estudio de tamamno realista.
2003 IEEE Bologna Power Tech Conference Proceedings,
The growth of power generation in Spain and several other countries is mainly based on the constr... more The growth of power generation in Spain and several other countries is mainly based on the construction of combined-cycle power plants. As the number of this type of plants increases, the gas and electricity systems are linked together. Therefore, power system reliability studies should consider the gas supply reliability. As a consequence, the new generation of reliability models should take into account the joint operation of electrical and gas systems. This paper presents a model to compute the maximum amount of power that can be supplied by the combined-cycle power plants in a system. The gas network is modeled. The effect of compressors to enlarge the transmission capacity of the network is included. The developed model will be integrated into a higher level model that analyzes the joint reliability of the electrical and gas systems. A case study based on the Belgian high-calorific gas network is analyzed.
IEEE Transactions on Power Systems, 2000
This paper presents a multi-period probabilistic production cost model. Dispatch intra-period and... more This paper presents a multi-period probabilistic production cost model. Dispatch intra-period and inter-period constraints are considered through the use of a facet LP formulation. An efficient solution procedure based on the Dantzig-Wolfe decomposition technique is developed. The work reported in this paper extends previous work in two respects: (i) inter-period constraints are rigurously treated, and (ii) a systematic general solution procedure is developed. Results for a large-scale case study are presented.
iit.upcomillas.es
(1) Universidad de Málaga Pza. El Ejido s/n 29013 Málaga (Spain). E-mail: estrada@dte.uma.es ... ... more (1) Universidad de Málaga Pza. El Ejido s/n 29013 Málaga (Spain). E-mail: estrada@dte.uma.es ... (2) Instituto de Investigación Tecnológica, ICAI, Universidad Pontificia Comillas C/ Santa Cruz de Marcenado, 26 28015 Madrid (Spain). E-mail: ...
2020 IEEE Global Engineering Education Conference (EDUCON)
Introductory courses on electric circuits at undergraduate level are usually presented in quite a... more Introductory courses on electric circuits at undergraduate level are usually presented in quite abstract terms, with questions and problems quite far from practical problems. This causes the students have difficulties to apply that theory to solve practical technical problems. On the other hand, electric circuits are everywhere in our lives, so we have plenty of real practical problems. Here we compile a selection of practical contexts suited for implementing Problem Based Learning approach in an introductory course on circuit analysis. And some examples describing the gamification process that uses these problems to build single-player role-playing games that fulfil the course contents and scheduling. The key point of the assessment and how it is related to the progress in the game is also described.
IEEE Transactions on Power Systems, 2000
Page 1. 554 IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 25, NO. 1, FEBRUARY 2010 Short-Term Trading ... more Page 1. 554 IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 25, NO. 1, FEBRUARY 2010 Short-Term Trading for a Wind Power Producer Juan M. Morales, Student Member, IEEE, Antonio J. Conejo, Fellow, IEEE, and Juan Pérez-Ruiz, Member, IEEE ...
Renewable energy & power quality journal, Apr 1, 2017
IEEE Transactions on Power Systems, 2007
This paper analyzes the behavior of Hong's point estimate methods to account for uncertainties on... more This paper analyzes the behavior of Hong's point estimate methods to account for uncertainties on the probabilistic power flow problem. This uncertainty may arise from different sources as load demand or generation unit outages. Point estimate methods constitute a remarkable tool to handle stochastic power system problems because good results can be achieved by using the same routines as those corresponding to deterministic problems, while keeping low the computational burden. In previous works related to power systems, only the two-point estimate method has been considered. In this paper, four different Hong's point estimate schemes are presented and tested on the probabilistic power flow problem. Binomial and normal distributions are used to model input random variables. Results for two different case studies, based on the IEEE 14-bus and IEEE 118-bus test systems, respectively, are presented and compared against those obtained from the Monte Carlo simulation. Particularly, this paper shows that the use of the 2m + 1 scheme provides the best performance when a high number of random variables, both continuous and discrete, are considered.
2013 IEEE Grenoble Conference, 2013
This paper presents an algorithm to solve a unit commitment problem that takes into account the u... more This paper presents an algorithm to solve a unit commitment problem that takes into account the uncertainty in the demand. This uncertainty is included in the optimization problem as a joint chance constraint that bounds the minimum value of the probability to jointly meet the deterministic power balance constraints. The demand is modeled as a multivariate, normally distributed, random variable and the correlation among different time periods is also considered. A deterministic mixed integer programming problem is sequentially solved until it converges to the solution of the chance-constrained optimization problem. Different approaches are presented to update the z-value used to transform the joint chance constraint into a set of deterministic constraints. Results from a realistic size case study are presented and the values obtained for the multivariate normal distribution probability are compared with the ones obtained by using a Monte Carlo simulation procedure.
This paper presents a model to assess the value of power injection from residential installations... more This paper presents a model to assess the value of power injection from residential installations, with photovoltaic (PV) generation and/or electric storage, to the main grid. This model is posed as a multi-period two-stage stochastic economic dispatch, including ramping constraints and operating reserves, from the point of view of a central operator. Two sources of uncertainty are distinguished and represented as mid- and short-term scenarios: mid-term variability along the year and short-term forecasting errors. A case study, based on the Spanish power system, is presented to show the value of injection on both the operation costs and CO2 emissions. Results obtained allow us to provide some recommendations on the deployment of these residential installations.
Energies, 2021
This paper presents a robust optimization model to find out the day-ahead energy and reserve to b... more This paper presents a robust optimization model to find out the day-ahead energy and reserve to be scheduled by an electric vehicle (EV) aggregator. Energy can be purchased from, and injected to, the distribution network, while upward and downward reserves can be also provided by the EV aggregator. Although it is an economically driven model, the focus of this work relies on the actual availability of the scheduled reserves in a future real-time. To this end, two main features stand out: on one hand, the uncertainty regarding the EV driven pattern is modeled through a robust approach and, on the other hand, a set of non-anticipativity constraints are included to prevent from unavailable future states. The proposed model is posed as a mixed-integer robust linear problem in which binary variables are used to consider the charging, discharging or idle status of the EV aggregator. Results over a 24-h case study show the capability of the proposed model.
2021 IEEE PES Innovative Smart Grid Technologies Conference - Latin America (ISGT Latin America), 2021
Optimal sizing and operation of a household with photovoltaic (PV) and storage requires a proper ... more Optimal sizing and operation of a household with photovoltaic (PV) and storage requires a proper consideration of some uncertain parameters, as demand and PV generation. A one-year case study, including several scenarios and hourly discretization, may be very efficiently solved using an off-the-shelf solver on a laptop. However, getting those data is not always an easy task. In this work, we study whether it would be possible to get an approximate solution by using aggregate measures for those uncertain parameters and how should the problem be transformed to handle that aggregated information. By taking into account the average values of consecutive periods, we propose a linear transformation of the constraints and a set of additional ones to get this goal. Results over a case study show that the proposed procedure provides reasonable values, although the precision could be improved if some additional information, apart from the average values of the uncertain input data, is considered.
2019 IEEE PES Innovative Smart Grid Technologies Europe (ISGT-Europe), Sep 1, 2019
IET Renewable Power Generation, 2019
This study presents a model to analyse the effect of an increasing level of residential and comme... more This study presents a model to analyse the effect of an increasing level of residential and commercial photovoltaic and storage devices, intended for self-consumption, on a power system. A whole year is focused and modelled through a set of selected representative days. A 24-h two-stage stochastic unit commitment is solved for each representative day and expected results are weighted to achieve annual expected results. This optimisation problem includes appropriate representation of the day-ahead and on-line operations and an adequate representation of the uncertainty associated with renewable sources and demand. The main contributions are: (i) the definition of a single model in which customers are price-makers and large-scale and customers’ installations are appropriately modelled, therefore bridging the current macroscopic and microscopic modelling approaches, and (ii) the division of customers into four non-overlapping groups, which allows a sensitivity analysis of the effect of each group. Five main results are focused: net demand, CO2 emissions, load factors, system operation cost, and customer savings. The model is applied to a case study based on the Spanish power system to show the model capability to quantify the effect of an increasing level of these promising technologies on a power system.
En esta tesis se desarrolla un modelo de costes de produccion multiperiodo para un sistema de ene... more En esta tesis se desarrolla un modelo de costes de produccion multiperiodo para un sistema de energia electrica, Este modelo integra la tecnica de simulacion probalista con la optimizacion en un problema de programacion lineal.Este problema, que inicialmente tiene estructura de plimatroide, puede incluir cualquier tipo de resticcion de despacho que pueda ser fomulada como una funcion lineal de los valores esperados de energia. La dimension del citado problema de optimziacion excede con creces la capacidad de los paquetes comerciales de optimizacion. En esta tesis se desarrollan dos metodos de resolucion alternativos altamente eficientes. El primero de ellos es una estrategia activa aplicada al metodo simples y el segundo se basa en la aplicacion de la tecnica de descomposicion de Dantizg-Wolfe. Ambos metodos se aplican a un caso de estudio de tamamno realista.
2003 IEEE Bologna Power Tech Conference Proceedings,
The growth of power generation in Spain and several other countries is mainly based on the constr... more The growth of power generation in Spain and several other countries is mainly based on the construction of combined-cycle power plants. As the number of this type of plants increases, the gas and electricity systems are linked together. Therefore, power system reliability studies should consider the gas supply reliability. As a consequence, the new generation of reliability models should take into account the joint operation of electrical and gas systems. This paper presents a model to compute the maximum amount of power that can be supplied by the combined-cycle power plants in a system. The gas network is modeled. The effect of compressors to enlarge the transmission capacity of the network is included. The developed model will be integrated into a higher level model that analyzes the joint reliability of the electrical and gas systems. A case study based on the Belgian high-calorific gas network is analyzed.
IEEE Transactions on Power Systems, 2000
This paper presents a multi-period probabilistic production cost model. Dispatch intra-period and... more This paper presents a multi-period probabilistic production cost model. Dispatch intra-period and inter-period constraints are considered through the use of a facet LP formulation. An efficient solution procedure based on the Dantzig-Wolfe decomposition technique is developed. The work reported in this paper extends previous work in two respects: (i) inter-period constraints are rigurously treated, and (ii) a systematic general solution procedure is developed. Results for a large-scale case study are presented.
iit.upcomillas.es
(1) Universidad de Málaga Pza. El Ejido s/n 29013 Málaga (Spain). E-mail: estrada@dte.uma.es ... ... more (1) Universidad de Málaga Pza. El Ejido s/n 29013 Málaga (Spain). E-mail: estrada@dte.uma.es ... (2) Instituto de Investigación Tecnológica, ICAI, Universidad Pontificia Comillas C/ Santa Cruz de Marcenado, 26 28015 Madrid (Spain). E-mail: ...
2020 IEEE Global Engineering Education Conference (EDUCON)
Introductory courses on electric circuits at undergraduate level are usually presented in quite a... more Introductory courses on electric circuits at undergraduate level are usually presented in quite abstract terms, with questions and problems quite far from practical problems. This causes the students have difficulties to apply that theory to solve practical technical problems. On the other hand, electric circuits are everywhere in our lives, so we have plenty of real practical problems. Here we compile a selection of practical contexts suited for implementing Problem Based Learning approach in an introductory course on circuit analysis. And some examples describing the gamification process that uses these problems to build single-player role-playing games that fulfil the course contents and scheduling. The key point of the assessment and how it is related to the progress in the game is also described.
IEEE Transactions on Power Systems, 2000
Page 1. 554 IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 25, NO. 1, FEBRUARY 2010 Short-Term Trading ... more Page 1. 554 IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 25, NO. 1, FEBRUARY 2010 Short-Term Trading for a Wind Power Producer Juan M. Morales, Student Member, IEEE, Antonio J. Conejo, Fellow, IEEE, and Juan Pérez-Ruiz, Member, IEEE ...