Giulio Ferro - Academia.edu (original) (raw)

Papers by Giulio Ferro

IAMES2024 is the third workshop focused on environmental modelling and integrated impact assessme... more IAMES2024 is the third workshop focused on environmental modelling and integrated impact assessment. These topics generally involve scientists from different disciplines, enterprises, policy makers, and other stakeholders for monitoring, management, and planning of environmental systems, and it finds application in multiple domains (risk management, pollution, social and life sciences, economics, power and energy, circular economy, …) in an integrated way. These topics are currently more and more interesting because of the high interest at the international level for environmental and energy sustainability, taking into account environmental impacts, economic issues, new technologies (energy production from renewables, smart grids, smart buildings, electric vehicles, storage systems, etc.), and new management tools (building automation systems, energy management systems, etc.). The methods and models that are particularly important to discuss in this workshop are those typical of automation and systems engineering: identification of models and simulation, data collection and elaboration, optimization, and control. It will serve as an international forum for interaction among scientists, enterprises, and decision-makers who are interested in defining, testing, and promoting models and methods to support policies for climate change, water resources management, air quality, agriculture, energy management, and any other activity that has an impact on human life or the environment itself.

2023 9th International Conference on Control, Decision and Information Technologies (CoDIT)

During the last years, the number of distributed generators has grown significantly and it is exp... more During the last years, the number of distributed generators has grown significantly and it is expected to get higher in the future. Several new technologies are being developed for this type of generation (including microturbines, photovoltaic plants, wind turbines and electrical storage systems) and have to be integrated in the electrical grid. In this framework, active loads (i.e., shift-able demands like electrical vehicles, intelligent buildings, etc.) and storage systems are crucial to make the distribution system more flexible and smart. The aim of this paper is to develop a model for the optimal integration of microgrids with renewable sources, smart buildings, and electrical vehicles (EVs) taking into account two different technologies: smart charging and vehicle to grid (V2G).

In this paper, a discrete event approach is proposed for the optimal charging of electrical vehic... more In this paper, a discrete event approach is proposed for the optimal charging of electrical vehicles in microgrids. In particular, the considered system is characterized by renewable energy sources (RES), non-renewable energy sources, electrical storage, a connection to the external grid and a charging station for electric vehicles (EVs). The decision variables are relevant to the schedule of production plants, storage systems and EVs' charging. The objective function to be minimized is related to the cost of purchasing energy from the external grid, the use of nonrenewable energy sources and tardiness of customer's service. The proposed approach is applied to a real case study and it is shown that it allows to considerably reduce the dimension of the problem (and thus the computational time required) as compared to a discrete-time approach.

In this paper, an optimization model for polygeneration microgrids is presented. In particular, t... more In this paper, an optimization model for polygeneration microgrids is presented. In particular, the system is characterized by trigeneration plants, renewables, district heating, thermal and electrical storage systems and flexible loads. The control variables are represented by the schedule of the power plants and of the deferrable demand, while the state variables are the energy stored in batteries and water tanks. The objective function minimizes operational costs in the day-ahead. The model is applied to the University of Genoa research infrastructures at Savona Campus, characterized by a Smart Polygeneration Microgrid and a Smart Energy Building.

IEEE Transactions on Control of Network Systems, Dec 1, 2022

IEEE Transactions on Automatic Control, Feb 1, 2022

We present a unified framework for distributed convex optimization using an algorithm called prox... more We present a unified framework for distributed convex optimization using an algorithm called proximal atomic coordination (PAC). PAC is based on the prox-linear approach and we prove that it achieves convergence in both objective values and distance to feasibility with rate o(1/τ), where τ is the number of algorithmic iterations. We further show that linear convergence is achieved when the objective functions are strongly convex and strongly smooth with condition number κ f , with the number of iterations on the order of square-root of κ f. This convergence rate matches the best known convergence results for distributed algorithms based on the popular alternating direction method of multipliers (ADMM) method. We also demonstrate that optimal decomposition strategies are related to a mincut graph partitioning problem on the underlying dependency hypergraph of the original optimization formulation. We then validate the effectiveness of the PAC algorithm and its extensions on a real-world optimization problem from power grid optimization, the relaxed optimal power flow. We compare the performance of the PAC algorithm with a standard variant of the popular distributed ADMM algorithm across different metrics: convergence in cost, convergence in local feasibility, convergence in global coordination, and computational time required for primal atomic updates.

IFAC-PapersOnLine, 2018

A bi-level Energy Management System (EMS) is here proposed for the day ahead schedule and real-ti... more A bi-level Energy Management System (EMS) is here proposed for the day ahead schedule and real-time optimal control of microgrids. The upper-level optimization problem (UDP) takes into account active and reactive power flows and a detailed formalization of the system model, with the aim of minimizing costs and emissions. For the lower level decision problem (LDP), the optimal results of the UDP are taken as reference values for the plant's schedule, which can be slightly modified in real time due to the actual values of renewables and energy demands. An analytical solution for the LDP has been found, which allows a fast and simple implementation of the microgrid's schedule.

IEEE Transactions on Automation Science and Engineering, 2022

In this article, we propose a new bi-level approach for the location and sizing of charging stati... more In this article, we propose a new bi-level approach for the location and sizing of charging stations (CSs) based on the integration of power distribution and traffic networks. At the lower level, the user choices and the energy demands are modeled through the user equilibrium (UE) traffic assignment conditions that are derived for the case of electric vehicles (EVs). At the higher level, an optimization problem is formalized for the optimal planning of locations, sizes, and unit prices of a set of new charging stations in a territory, which embeds the UE conditions and the power flow model as constraints. The main novelties lie in the integration of traffic and electric networks, the optimization problem formalization, and the inclusion of detailed electrical issues [such as the complete alternating current (AC) power flow equations and the modeling of CSs with different phases]. The developed model has been applied to a case study in the Genoa Municipality. Note to Practitioners—In the past decade, particular attention has been posed on EVs and renewable resources to reduce pollutants’ emissions. Critical issues regard the setting of adequate recharging infrastructure and the integration of huge distributed and intermittent loads and production into the electrical grid. This article aims to provide a bi-level optimization model that can be used by companies or public administrations that want to install charging stations in a territory. In particular, the transportation and the electrical networks are integrated: at a lower level, the UE traffic assignment conditions are derived to represent users’ choices and to assess the energy demand. At the upper level, an optimization problem is formalized, to minimize costs of installation and power losses and to maximize benefits, which embeds as constraints the UE conditions for the case of EVs and the model of the electrical grid (load flow equations, bounds over-voltage, apparent power, etc.).

Energy, May 1, 2020

The development of policies for sustainable development has led to an increase in electric vehicl... more The development of policies for sustainable development has led to an increase in electric vehicles (EVs). This has given rise to new problems, such as the location and sizing of charging stations over the considered traffic network. The solution of such problems requires the application of analysis techniques in order to predict the joint allocation of transportation and energy demands. In this paper, an approach is proposed that extends the User Equilibrium (UE) principle in order to determine, besides to the flow over the network links, the service requests from the drivers to the various service stations. The application of this method is preliminary for the statement of any problem related to the optimization of location and sizing of service stations. The proposed approach is applied to a case study in Genoa Municipality (Liguria Region).

Microgrids that are able to work both in grid-connected and islanded modes need a hierarchical st... more Microgrids that are able to work both in grid-connected and islanded modes need a hierarchical structure based on tertiary, secondary and primary controllers, which are fundamental for the maintenance of frequency and stability. In this paper, two types of controllers are formalized and solved as optimal control problems: tertiary and secondary controls. For secondary control two different scaled single-phase models are used for the microgrid: one merely electric and the other one based on the synchronous machine. The approach is applied to a real test-bed facility: the University of Genova Smart Polygeneration Microgrid (SPM). Specifically, a portion of the microgrid is selected to study the behavior in islanded mode. The considered grid is characterized by: a diesel engine connected to an electrically excited synchronous generator, a photovoltaic plant and an electric storage (these last two are respectively connected to a couple of inverters set as current source generator (CSI)).

IFAC-PapersOnLine, 2020

In the present paper we introduce a new distributed optimization approach to the solution of gene... more In the present paper we introduce a new distributed optimization approach to the solution of general Optimal Power Flow problem for unbalanced and mesh networks. A new convex formulation, based on McCormick Envelopes, is proposed with a decomposition profile and a distributed approach based on proximal coordination. The resulting algorithm is shown to converge with a rate of o(1/τ), where τ is the number of iterations. The approach is validated on a modified IEEE 13 bus network, with added distributed energy resources including distributed generation and demand response. Keywords: Smart grids, modeling of power systems, optimal operation and control of power systems, optimization and control of large-scale network systems, decentralized and distributed control.

The present paper describes an Energy Management System developed to operate a polygeneration mic... more The present paper describes an Energy Management System developed to operate a polygeneration microgrid where demand response strategies are applied. The proposed tool is characterized by a detailed representation of generation units and flexible loads, as well as electric/thermal networks and storage systems. Furthermore, the interaction between the microgrid and a smart building is modeled, taking into account the inner comfort level in the objective function of the optimization problem. The tool is applied to a real case study represented by the Savona Campus of the University of Genoa in Italy, where a polygeneration microgrid and a smart building are present.

IFAC-PapersOnLine, 2018

The exploitation of biomass in power production systems is particularly attractive to reduce CO 2... more The exploitation of biomass in power production systems is particularly attractive to reduce CO 2 emissions. However, the installation of biomass-fed power plants is not always technically and economically competitive with respect to traditional fossil fuels. This paper aims to provide a decision support system that can help the decision maker in assessing the feasibility of the plant, from a technical and economic point of view, and to provide its optimal design. The model is adapted for a plant that can produce pellets, electricity, and heat, through the gasification process. The developed model is applied to a real case study in the Alessandria Province (Italy).

International Journal of Electrical Power & Energy Systems, Dec 1, 2018

Islanded microgrids are assuming a key role for the support in the distribution grid's management... more Islanded microgrids are assuming a key role for the support in the distribution grid's management, which is more and more difficult due to the massive increase of distributed generation and energy production plants from renewable resources. In this paper, a new architecture for the optimal control of tertiary and secondary levels in small-size islanded microgrids is proposed. Specifically, at each optimization step, by using a receding horizon approach, the tertiary control provides the optimal power schedule for the microgrid on the basis of economic and environmental criteria. Then, the secondary control, to provide set points for primary control, uses another objective function that minimizes the quadratic deviation from the reference values provided by the tertiary level and the desired frequency for good performances. The approach is applied to a real case study (a portion of the Savona Campus Smart Polygeneration Microgrid) characterized by a diesel engine connected to a synchronous generator, a photovoltaic plant, and an electrical storage system. This paper considers a real case study, (i.e., a portion of the University of Genova SPM (Smart Polygeneration Microgrid) [5]) for islanded mode operations. It consists of a diesel generator, a photovoltaic unit, a storage system and, a load. In fact, the developed models are thought to be used in small size microgrids like buildings, groups of

IGI Global eBooks, 2022

The relevance of electric vehicles (EVs) is increasing along with the relative issues. The defini... more The relevance of electric vehicles (EVs) is increasing along with the relative issues. The definition of smart policies for scheduling the EVs charging process represents one of the most important problems. A discrete-event approach is proposed for the optimal scheduling of EVs in microgrids. This choice is due to the necessity of limiting the number of the decision variables, which rapidly grows when a small-time discretization step is chosen. The considered optimization problem regards the charging of a series of vehicles in a microgrid characterized by renewable energy source, a storage element, the connection to the main grid, and a charging station. The objective function to be minimized results from the weighted sum of the cost for purchasing energy from the external grid, the weighted tardiness of the services provided, and a cost related to the occupancy of the socket. The approach is tested on a real case study.

IEEE Systems Journal, Jun 1, 2023

IFAC-PapersOnLine, 2020

A new bi-level approach is proposed for the location and sizing of charging stations, considering... more A new bi-level approach is proposed for the location and sizing of charging stations, considering both the transportation and energy demands. The lower level considers the User Equilibrium traffic assignment conditions for Electric Vehicles (EVs) which are derived and inserted as constraints in the overall optimization problem. The higher level presents the formalization of an optimization problem for the optimal planning of locations, sizes and unit prices of a set of new charging stations in a territory characterized by the presence of an already existing set of charging stations. A case study in the Genoa Municipality is considered for the application of the proposed model.

IAMES2024 is the third workshop focused on environmental modelling and integrated impact assessme... more IAMES2024 is the third workshop focused on environmental modelling and integrated impact assessment. These topics generally involve scientists from different disciplines, enterprises, policy makers, and other stakeholders for monitoring, management, and planning of environmental systems, and it finds application in multiple domains (risk management, pollution, social and life sciences, economics, power and energy, circular economy, …) in an integrated way. These topics are currently more and more interesting because of the high interest at the international level for environmental and energy sustainability, taking into account environmental impacts, economic issues, new technologies (energy production from renewables, smart grids, smart buildings, electric vehicles, storage systems, etc.), and new management tools (building automation systems, energy management systems, etc.). The methods and models that are particularly important to discuss in this workshop are those typical of automation and systems engineering: identification of models and simulation, data collection and elaboration, optimization, and control. It will serve as an international forum for interaction among scientists, enterprises, and decision-makers who are interested in defining, testing, and promoting models and methods to support policies for climate change, water resources management, air quality, agriculture, energy management, and any other activity that has an impact on human life or the environment itself.

2023 9th International Conference on Control, Decision and Information Technologies (CoDIT)

During the last years, the number of distributed generators has grown significantly and it is exp... more During the last years, the number of distributed generators has grown significantly and it is expected to get higher in the future. Several new technologies are being developed for this type of generation (including microturbines, photovoltaic plants, wind turbines and electrical storage systems) and have to be integrated in the electrical grid. In this framework, active loads (i.e., shift-able demands like electrical vehicles, intelligent buildings, etc.) and storage systems are crucial to make the distribution system more flexible and smart. The aim of this paper is to develop a model for the optimal integration of microgrids with renewable sources, smart buildings, and electrical vehicles (EVs) taking into account two different technologies: smart charging and vehicle to grid (V2G).

In this paper, a discrete event approach is proposed for the optimal charging of electrical vehic... more In this paper, a discrete event approach is proposed for the optimal charging of electrical vehicles in microgrids. In particular, the considered system is characterized by renewable energy sources (RES), non-renewable energy sources, electrical storage, a connection to the external grid and a charging station for electric vehicles (EVs). The decision variables are relevant to the schedule of production plants, storage systems and EVs' charging. The objective function to be minimized is related to the cost of purchasing energy from the external grid, the use of nonrenewable energy sources and tardiness of customer's service. The proposed approach is applied to a real case study and it is shown that it allows to considerably reduce the dimension of the problem (and thus the computational time required) as compared to a discrete-time approach.

In this paper, an optimization model for polygeneration microgrids is presented. In particular, t... more In this paper, an optimization model for polygeneration microgrids is presented. In particular, the system is characterized by trigeneration plants, renewables, district heating, thermal and electrical storage systems and flexible loads. The control variables are represented by the schedule of the power plants and of the deferrable demand, while the state variables are the energy stored in batteries and water tanks. The objective function minimizes operational costs in the day-ahead. The model is applied to the University of Genoa research infrastructures at Savona Campus, characterized by a Smart Polygeneration Microgrid and a Smart Energy Building.

IEEE Transactions on Control of Network Systems, Dec 1, 2022

IEEE Transactions on Automatic Control, Feb 1, 2022

We present a unified framework for distributed convex optimization using an algorithm called prox... more We present a unified framework for distributed convex optimization using an algorithm called proximal atomic coordination (PAC). PAC is based on the prox-linear approach and we prove that it achieves convergence in both objective values and distance to feasibility with rate o(1/τ), where τ is the number of algorithmic iterations. We further show that linear convergence is achieved when the objective functions are strongly convex and strongly smooth with condition number κ f , with the number of iterations on the order of square-root of κ f. This convergence rate matches the best known convergence results for distributed algorithms based on the popular alternating direction method of multipliers (ADMM) method. We also demonstrate that optimal decomposition strategies are related to a mincut graph partitioning problem on the underlying dependency hypergraph of the original optimization formulation. We then validate the effectiveness of the PAC algorithm and its extensions on a real-world optimization problem from power grid optimization, the relaxed optimal power flow. We compare the performance of the PAC algorithm with a standard variant of the popular distributed ADMM algorithm across different metrics: convergence in cost, convergence in local feasibility, convergence in global coordination, and computational time required for primal atomic updates.

IFAC-PapersOnLine, 2018

A bi-level Energy Management System (EMS) is here proposed for the day ahead schedule and real-ti... more A bi-level Energy Management System (EMS) is here proposed for the day ahead schedule and real-time optimal control of microgrids. The upper-level optimization problem (UDP) takes into account active and reactive power flows and a detailed formalization of the system model, with the aim of minimizing costs and emissions. For the lower level decision problem (LDP), the optimal results of the UDP are taken as reference values for the plant's schedule, which can be slightly modified in real time due to the actual values of renewables and energy demands. An analytical solution for the LDP has been found, which allows a fast and simple implementation of the microgrid's schedule.

IEEE Transactions on Automation Science and Engineering, 2022

In this article, we propose a new bi-level approach for the location and sizing of charging stati... more In this article, we propose a new bi-level approach for the location and sizing of charging stations (CSs) based on the integration of power distribution and traffic networks. At the lower level, the user choices and the energy demands are modeled through the user equilibrium (UE) traffic assignment conditions that are derived for the case of electric vehicles (EVs). At the higher level, an optimization problem is formalized for the optimal planning of locations, sizes, and unit prices of a set of new charging stations in a territory, which embeds the UE conditions and the power flow model as constraints. The main novelties lie in the integration of traffic and electric networks, the optimization problem formalization, and the inclusion of detailed electrical issues [such as the complete alternating current (AC) power flow equations and the modeling of CSs with different phases]. The developed model has been applied to a case study in the Genoa Municipality. Note to Practitioners—In the past decade, particular attention has been posed on EVs and renewable resources to reduce pollutants’ emissions. Critical issues regard the setting of adequate recharging infrastructure and the integration of huge distributed and intermittent loads and production into the electrical grid. This article aims to provide a bi-level optimization model that can be used by companies or public administrations that want to install charging stations in a territory. In particular, the transportation and the electrical networks are integrated: at a lower level, the UE traffic assignment conditions are derived to represent users’ choices and to assess the energy demand. At the upper level, an optimization problem is formalized, to minimize costs of installation and power losses and to maximize benefits, which embeds as constraints the UE conditions for the case of EVs and the model of the electrical grid (load flow equations, bounds over-voltage, apparent power, etc.).

Energy, May 1, 2020

The development of policies for sustainable development has led to an increase in electric vehicl... more The development of policies for sustainable development has led to an increase in electric vehicles (EVs). This has given rise to new problems, such as the location and sizing of charging stations over the considered traffic network. The solution of such problems requires the application of analysis techniques in order to predict the joint allocation of transportation and energy demands. In this paper, an approach is proposed that extends the User Equilibrium (UE) principle in order to determine, besides to the flow over the network links, the service requests from the drivers to the various service stations. The application of this method is preliminary for the statement of any problem related to the optimization of location and sizing of service stations. The proposed approach is applied to a case study in Genoa Municipality (Liguria Region).

Microgrids that are able to work both in grid-connected and islanded modes need a hierarchical st... more Microgrids that are able to work both in grid-connected and islanded modes need a hierarchical structure based on tertiary, secondary and primary controllers, which are fundamental for the maintenance of frequency and stability. In this paper, two types of controllers are formalized and solved as optimal control problems: tertiary and secondary controls. For secondary control two different scaled single-phase models are used for the microgrid: one merely electric and the other one based on the synchronous machine. The approach is applied to a real test-bed facility: the University of Genova Smart Polygeneration Microgrid (SPM). Specifically, a portion of the microgrid is selected to study the behavior in islanded mode. The considered grid is characterized by: a diesel engine connected to an electrically excited synchronous generator, a photovoltaic plant and an electric storage (these last two are respectively connected to a couple of inverters set as current source generator (CSI)).

IFAC-PapersOnLine, 2020

In the present paper we introduce a new distributed optimization approach to the solution of gene... more In the present paper we introduce a new distributed optimization approach to the solution of general Optimal Power Flow problem for unbalanced and mesh networks. A new convex formulation, based on McCormick Envelopes, is proposed with a decomposition profile and a distributed approach based on proximal coordination. The resulting algorithm is shown to converge with a rate of o(1/τ), where τ is the number of iterations. The approach is validated on a modified IEEE 13 bus network, with added distributed energy resources including distributed generation and demand response. Keywords: Smart grids, modeling of power systems, optimal operation and control of power systems, optimization and control of large-scale network systems, decentralized and distributed control.

The present paper describes an Energy Management System developed to operate a polygeneration mic... more The present paper describes an Energy Management System developed to operate a polygeneration microgrid where demand response strategies are applied. The proposed tool is characterized by a detailed representation of generation units and flexible loads, as well as electric/thermal networks and storage systems. Furthermore, the interaction between the microgrid and a smart building is modeled, taking into account the inner comfort level in the objective function of the optimization problem. The tool is applied to a real case study represented by the Savona Campus of the University of Genoa in Italy, where a polygeneration microgrid and a smart building are present.

IFAC-PapersOnLine, 2018

The exploitation of biomass in power production systems is particularly attractive to reduce CO 2... more The exploitation of biomass in power production systems is particularly attractive to reduce CO 2 emissions. However, the installation of biomass-fed power plants is not always technically and economically competitive with respect to traditional fossil fuels. This paper aims to provide a decision support system that can help the decision maker in assessing the feasibility of the plant, from a technical and economic point of view, and to provide its optimal design. The model is adapted for a plant that can produce pellets, electricity, and heat, through the gasification process. The developed model is applied to a real case study in the Alessandria Province (Italy).

International Journal of Electrical Power & Energy Systems, Dec 1, 2018

Islanded microgrids are assuming a key role for the support in the distribution grid's management... more Islanded microgrids are assuming a key role for the support in the distribution grid's management, which is more and more difficult due to the massive increase of distributed generation and energy production plants from renewable resources. In this paper, a new architecture for the optimal control of tertiary and secondary levels in small-size islanded microgrids is proposed. Specifically, at each optimization step, by using a receding horizon approach, the tertiary control provides the optimal power schedule for the microgrid on the basis of economic and environmental criteria. Then, the secondary control, to provide set points for primary control, uses another objective function that minimizes the quadratic deviation from the reference values provided by the tertiary level and the desired frequency for good performances. The approach is applied to a real case study (a portion of the Savona Campus Smart Polygeneration Microgrid) characterized by a diesel engine connected to a synchronous generator, a photovoltaic plant, and an electrical storage system. This paper considers a real case study, (i.e., a portion of the University of Genova SPM (Smart Polygeneration Microgrid) [5]) for islanded mode operations. It consists of a diesel generator, a photovoltaic unit, a storage system and, a load. In fact, the developed models are thought to be used in small size microgrids like buildings, groups of

IGI Global eBooks, 2022

The relevance of electric vehicles (EVs) is increasing along with the relative issues. The defini... more The relevance of electric vehicles (EVs) is increasing along with the relative issues. The definition of smart policies for scheduling the EVs charging process represents one of the most important problems. A discrete-event approach is proposed for the optimal scheduling of EVs in microgrids. This choice is due to the necessity of limiting the number of the decision variables, which rapidly grows when a small-time discretization step is chosen. The considered optimization problem regards the charging of a series of vehicles in a microgrid characterized by renewable energy source, a storage element, the connection to the main grid, and a charging station. The objective function to be minimized results from the weighted sum of the cost for purchasing energy from the external grid, the weighted tardiness of the services provided, and a cost related to the occupancy of the socket. The approach is tested on a real case study.

IEEE Systems Journal, Jun 1, 2023

IFAC-PapersOnLine, 2020

A new bi-level approach is proposed for the location and sizing of charging stations, considering... more A new bi-level approach is proposed for the location and sizing of charging stations, considering both the transportation and energy demands. The lower level considers the User Equilibrium traffic assignment conditions for Electric Vehicles (EVs) which are derived and inserted as constraints in the overall optimization problem. The higher level presents the formalization of an optimization problem for the optimal planning of locations, sizes and unit prices of a set of new charging stations in a territory characterized by the presence of an already existing set of charging stations. A case study in the Genoa Municipality is considered for the application of the proposed model.