energies-logo

Journal Browser

Journal Browser

Optimal Control of Hybrid Systems and Renewable Energies

A special issue of Energies (ISSN 1996-1073). This special issue belongs to the section "F: Electrical Engineering".

Deadline for manuscript submissions: closed (31 January 2020) | Viewed by 42196

Printed Edition Available!
A printed edition of this Special Issue is available here.

Special Issue Editors


E-Mail Website
Guest Editor
DIBRIS—Department of Informatics, Bioengineering, Robotics and Systems Engineering, University of Genova, 16145 Genova, Italy
Interests: optimization; control; planning and control of smart grids; electric vehicles
Special Issues, Collections and Topics in MDPI journals

E-Mail Website
Guest Editor
Department of Electrical, Electronics and Telecommunication Engineering and Naval Architecture, University of Genova, Genova, Italy
Interests: renewable and decentralized energy resources

Special Issue Information

Dear Colleagues,

International policies for sustainable development have led to an increase of distributed power production based on renewable resources. However, on the one hand, their intermittency may create problems for the electrical grid, and, on the other hand, they are costly. It is necessary to define new technological solutions that can reduce costs and new control strategies to optimally manage renewable resources and to integrate them into the new energy systems, which are more and more characterized by the close interaction between different energy vectors and their networks (thermal, electrical, etc.) and by a transition from a centralized structure to a decentralized one (both in terms of sources and controls).

The main aim of this Special Issue is to collect papers in the field of the optimal control of power and energy production from renewable resources (wind, PV, biomass, hydrogen, etc.). The specific topics of the Special Issue (but not limited to) are:

  • Modelling and control of wind turbines, PV and solar thermal plants, etc.;
  • Optimal control of hybrid systems (wind, hydrogen, fuel cells, hydro-electric plants, etc.);
  • Operational management of biomass-based power plants;
  • Optimization and control of energy systems;
  • Stochastic optimization;
  • Model predictive control;
  • Distributed optimization;
  • Optimal control of storage systems;
  • Modelling and control of flexible loads.

Prof. Dr. Michela Robba
Prof. Dr. Mansueto Rossi
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Energies is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • optimal control
  • optimization
  • renewable resources
  • storage systems
  • power converters
  • wind
  • biomass
  • photovoltaics
  • solar thermal

Benefits of Publishing in a Special Issue

  • Ease of navigation: Grouping papers by topic helps scholars navigate broad scope journals more efficiently.
  • Greater discoverability: Special Issues support the reach and impact of scientific research. Articles in Special Issues are more discoverable and cited more frequently.
  • Expansion of research network: Special Issues facilitate connections among authors, fostering scientific collaborations.
  • External promotion: Articles in Special Issues are often promoted through the journal's social media, increasing their visibility.
  • e-Book format: Special Issues with more than 10 articles can be published as dedicated e-books, ensuring wide and rapid dissemination.

Further information on MDPI's Special Issue polices can be found here.

Published Papers (12 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Editorial

Jump to: Research

3 pages, 178 KiB  
Editorial
Optimal Control of Hybrid Systems and Renewable Energies
by Michela Robba and Mansueto Rossi
Energies 2022, 15(1), 78; https://doi.org/10.3390/en15010078 - 23 Dec 2021
Cited by 3 | Viewed by 1880
Abstract
International policies for sustainable development have led to an increase in distributed power production based on renewable resources [...] Full article
(This article belongs to the Special Issue Optimal Control of Hybrid Systems and Renewable Energies)

Research

Jump to: Editorial

23 pages, 6650 KiB  
Article
A Building Energy Management System Based on an Equivalent Electric Circuit Model
by Giovanni Bianco, Stefano Bracco, Federico Delfino, Lorenzo Gambelli, Michela Robba and Mansueto Rossi
Energies 2020, 13(7), 1689; https://doi.org/10.3390/en13071689 - 3 Apr 2020
Cited by 18 | Viewed by 3314
Abstract
In recent decades, many EU and national regulations have been issued in order to increase the energy efficiency in different sectors and, consequently, to reduce environmental pollution. In the building sector, energy efficiency interventions are usually based on the use of innovative insulated [...] Read more.
In recent decades, many EU and national regulations have been issued in order to increase the energy efficiency in different sectors and, consequently, to reduce environmental pollution. In the building sector, energy efficiency interventions are usually based on the use of innovative insulated materials and on the installation of cogeneration and tri-generation units, as well as solar technologies. New and retrofitted buildings are more and more commonly being called “smart buildings”, since they are characterized by the installation of electric and thermal power generation units, energy storage systems, and flexible loads; the presence of such technologies determines the necessity of installing Building Energy Management Systems (BEMSs), which are used to optimally manage their operation. The present paper proposes a BEMS for a smart building, equipped with plants based on renewables (photovoltaics, solar thermal panels, and geothermal heat pump), where the heating and cooling demand are satisfied by a Heating, Ventilation and Air Conditioning System (HVAC) fed by a geothermal heat pump. The developed BEMS is composed of two different modules: an optimization tool used to optimally manage the HVAC plant, in order to guarantee a desired level of comfort inside rooms, and a simulation tool, based on an equivalent electric circuit model and used to evaluate the thermal dynamic behavior of the building. The paper describes the two modules and shows the main results of the validation phase that has been conducted on a real test-case represented by the Smart Energy Building (SEB) located at the Savona Campus of the University of Genoa, Italy. Full article
(This article belongs to the Special Issue Optimal Control of Hybrid Systems and Renewable Energies)
Show Figures

Figure 1

37 pages, 9568 KiB  
Article
Operational Simulation Environment for SCADA Integration of Renewable Resources
by Diego Francisco Larios, Enrique Personal, Antonio Parejo, Sebastián García, Antonio García and Carlos Leon
Energies 2020, 13(6), 1333; https://doi.org/10.3390/en13061333 - 13 Mar 2020
Cited by 5 | Viewed by 4164
Abstract
The complexity of power systems is rising mainly due to the expansion of renewable energy generation. Due to the enormous variability and uncertainty associated with these types of resources, they require sophisticated planning tools so that they can be used appropriately. In this [...] Read more.
The complexity of power systems is rising mainly due to the expansion of renewable energy generation. Due to the enormous variability and uncertainty associated with these types of resources, they require sophisticated planning tools so that they can be used appropriately. In this sense, several tools for the simulation of renewable energy assets have been proposed. However, they are traditionally focused on the simulation of the generation process, leaving the operation of these systems in the background. Conversely, more expert SCADA operators for the management of renewable power plants are required, but their training is not an easy task. SCADA operation is usually complex, due to the wide set of information available. In this sense, simulation or co-simulation tools can clearly help to reduce the learning curve and improve their skills. Therefore, this paper proposes a useful simulator based on a JavaScript engine that can be easily connected to any renewable SCADAs, making it possible to perform different simulated scenarios for novel operator training, as if it were a real facility. Using this tool, the administrators can easily program those scenarios allowing them to sort out the lack of support found in setting up facilities and training of novel operator tasks. Additionally, different renewable energy generation models that can be implemented in the proposed simulator are described. Later, as a use example of this tool, a study case is also performed. It proposes three different wind farm generation facility models, based on different turbine models: one with the essential generation turbine function obtained from the manufacturer curve, another with an empirical model using monotonic splines, and the last one adding the most important operational states, making it possible to demonstrate the usefulness of the proposed simulation tool. Full article
(This article belongs to the Special Issue Optimal Control of Hybrid Systems and Renewable Energies)
Show Figures

Figure 1

14 pages, 3994 KiB  
Article
Economy Mode Setting Device for Wind-Diesel Power Plants
by Andrey Dar’enkov, Elena Sosnina, Andrey Shalukho and Ivan Lipuzhin
Energies 2020, 13(5), 1274; https://doi.org/10.3390/en13051274 - 10 Mar 2020
Cited by 5 | Viewed by 2567
Abstract
The article is devoted to the problem of reducing fuel consumption in a diesel generator set (DGS) as a part of a wind-diesel power plant (WDPP). The object of the research is a variable speed DGS. The goal is to develop the WDPP [...] Read more.
The article is devoted to the problem of reducing fuel consumption in a diesel generator set (DGS) as a part of a wind-diesel power plant (WDPP). The object of the research is a variable speed DGS. The goal is to develop the WDPP intelligent control system, providing an optimal shaft speed of an internal combustion engine (ICE). The basis of the intelligent control system is an economy mode setting device (EMSD), which controls the fuel supply to the ICE. The functional chart of EMSD has been presented. The main EMSD blocks contain a controller and an associative memory block. The associative memory block is a software model of an artificial neural network that determines the optimal shaft speed of the ICE. An algorithm for the WDPP intelligent control system has been developed and tested using the WDPP Simulink model. The EMSD prototype has been created, and its research has been conducted. Dependences of the change in specific and absolute fuel consumption on the load power have been obtained for two 4 kW DGS: with constant rotation speed and variable rotation speed DGS with EMSD. It has been established that the use of EMSD in the mode of low loads allow one to reduce fuel consumption by almost 30%. The error in determining the optimal engine speed using EMSD prototype is not more than 15%. Full article
(This article belongs to the Special Issue Optimal Control of Hybrid Systems and Renewable Energies)
Show Figures

Figure 1

23 pages, 7395 KiB  
Article
Optimal Control of Multiple Microgrids and Buildings by an Aggregator
by Giulio Ferro, Riccardo Minciardi, Luca Parodi, Michela Robba and Mansueto Rossi
Energies 2020, 13(5), 1058; https://doi.org/10.3390/en13051058 - 27 Feb 2020
Cited by 14 | Viewed by 2588
Abstract
The electrical grid has been changing in the last decade due to the presence of renewables, distributed generation, storage systems, microgrids, and electric vehicles. The introduction of new legislation and actors in the smart grid’s system opens new challenges for the activities of [...] Read more.
The electrical grid has been changing in the last decade due to the presence of renewables, distributed generation, storage systems, microgrids, and electric vehicles. The introduction of new legislation and actors in the smart grid’s system opens new challenges for the activities of companies, and for the development of new energy management systems, models, and methods. A new optimization-based bi-level architecture is proposed for an aggregator of consumers in the balancing market, in which incentives for local users (i.e., microgrids, buildings) are considered, as well as flexibility and a fair assignment in reducing the overall load. At the lower level, consumers try to follow the aggregator’s reference values and perform demand response programs to contain their costs and satisfy demands. The approach is applied to a real case study. Full article
(This article belongs to the Special Issue Optimal Control of Hybrid Systems and Renewable Energies)
Show Figures

Figure 1

24 pages, 7157 KiB  
Article
Energy-Storage-Based Smart Electrical Infrastructure and Regenerative Braking Energy Management in AC-Fed Railways with Neutral Zones
by Zhixuan Gao, Qiwei Lu, Cong Wang, Junqing Fu and Bangbang He
Energies 2019, 12(21), 4053; https://doi.org/10.3390/en12214053 - 24 Oct 2019
Cited by 20 | Viewed by 2918
Abstract
This paper presents a modified power supply system based on the current alternating current (AC)-fed railways with neutral zones that can further improve the eco-friendliness and smart level of railways. The modified system complements the existing infrastructure with additional energy-storage-based smart electrical infrastructure. [...] Read more.
This paper presents a modified power supply system based on the current alternating current (AC)-fed railways with neutral zones that can further improve the eco-friendliness and smart level of railways. The modified system complements the existing infrastructure with additional energy-storage-based smart electrical infrastructure. This infrastructure comprises power electronic devices with energy storage system connected in parallel to both sides of each neutral zone in the traction substations, power electronic devices connected in parallel to both sides of each neutral zone in section posts, and an energy management system. The description and functions of such a modified system are outlined in this paper. The system allows for the centralized- and distributed-control of different functions via an energy management system. In addition, a control algorithm is proposed, based on the modified system for regenerative braking energy utilization. This would ensure that all the regenerative braking energy in the whole railway electrical system is used more efficiently. Finally, a modified power supply system with eight power supply sections is considered to be a case study; furthermore, the advantages of the proposed system and the effectiveness of the proposed control algorithm are verified. Full article
(This article belongs to the Special Issue Optimal Control of Hybrid Systems and Renewable Energies)
Show Figures

Graphical abstract

19 pages, 10877 KiB  
Article
A Comprehensive Inverter-BESS Primary Control for AC Microgrids
by Michele Fusero, Andrew Tuckey, Alessandro Rosini, Pietro Serra, Renato Procopio and Andrea Bonfiglio
Energies 2019, 12(20), 3810; https://doi.org/10.3390/en12203810 - 9 Oct 2019
Cited by 39 | Viewed by 4921
Abstract
This paper proposes the design of a comprehensive inverter-BESS primary control capable of providing satisfactory performances both in grid-connected and islanded configurations as required by international standards and grid codes, such as IEEE Std. 1547. Such control guarantees smooth and fast dynamic behavior [...] Read more.
This paper proposes the design of a comprehensive inverter-BESS primary control capable of providing satisfactory performances both in grid-connected and islanded configurations as required by international standards and grid codes, such as IEEE Std. 1547. Such control guarantees smooth and fast dynamic behavior of the converter in islanded configuration as well as fast power control and voltage-frequency support in grid-connected mode. The performances of the proposed primary control are assessed by means of EMT (ElectroMagnetic Transients) simulations in the dedicated software DIgSILENT PowerFactory® (Germany, Gomaringen) . The simulation results show that the proposed BESS (Battery Energy Storage System) primary control is able to regulate frequency and voltage in Grid-Forming mode independently of the number of paralleled generators. This is achieved adopting a virtual generator technique which presents several advantages compared to the conventional one. Moreover, the proposed control can be switched to Grid-Support mode in order to provide fast control actions to allow frequency and voltage support as well as power control following the reference signals from the secondary level. Full article
(This article belongs to the Special Issue Optimal Control of Hybrid Systems and Renewable Energies)
Show Figures

Figure 1

15 pages, 2187 KiB  
Article
A Comparison of the Dynamic Performance of Conventional and Ternary Pumped Storage Hydro
by Soumyadeep Nag, Kwang Y. Lee and D. Suchitra
Energies 2019, 12(18), 3513; https://doi.org/10.3390/en12183513 - 12 Sep 2019
Cited by 20 | Viewed by 4530
Abstract
With decreasing costs of renewable energy harvesting devices, penetration of solar panels and wind turbines have increased manifold. Under such high levels of penetration, coping with increased intermittency and unpredictability and maintaining power system resiliency under reduced inertia conditions has become a critical [...] Read more.
With decreasing costs of renewable energy harvesting devices, penetration of solar panels and wind turbines have increased manifold. Under such high levels of penetration, coping with increased intermittency and unpredictability and maintaining power system resiliency under reduced inertia conditions has become a critical issue. Pumped storage hydro (PSH) is the most matured and economic form of storage that can serve the purpose of capacity for over 4 to 8 h. However, to increase network inertia and add required flexibility to low inertia power systems, significant paradigm shifting modifications have been engineered to result in the development of Ternary PSH (TPSH). In this paper a test system to consider governor interaction is constructed. The dynamic models of conventional PSH (CPSH) and TPSH are constructed and integrated to the test system to examine the effect of CPSH and TPSH in the hydraulic short circuit (TPSH-HSC). The ability and the effect of mode change (from pump to turbine) without the loss synchronism of TPSH has also been examined. Results display the superior capability and effect of TPSH with its HSC capability to contribute to frequency regulation during pumping mode and the effect of rapid mode change, as compared to its primitive alternative, CPSH. Full article
(This article belongs to the Special Issue Optimal Control of Hybrid Systems and Renewable Energies)
Show Figures

Graphical abstract

12 pages, 2303 KiB  
Article
A Feedback Control Loop Optimisation Methodology for Floating Offshore Wind Turbines
by Joannes Olondriz, Josu Jugo, Iker Elorza and Santiago Alonso-Quesada and Aron Pujana-Arrese
Energies 2019, 12(18), 3490; https://doi.org/10.3390/en12183490 - 10 Sep 2019
Cited by 12 | Viewed by 3121
Abstract
Wind turbines usually present several feedback control loops to improve or counteract some specific performance or behaviour of the system. It is common to find these multiple feedback control loops in Floating Offshore Wind Turbines where the system perferformance is highly influenced by [...] Read more.
Wind turbines usually present several feedback control loops to improve or counteract some specific performance or behaviour of the system. It is common to find these multiple feedback control loops in Floating Offshore Wind Turbines where the system perferformance is highly influenced by the platform dynamics. This is the case of the Aerodynamic Platform Stabiliser and Wave Rejection feedback control loops which are complementaries to the conventional generator speed PI control loop when it is working in an above rated wind speed region. The multiple feedback control loops sometimes can be tedious to manually improve the initial tuning. Therefore, this article presents a novel optimisation methodology based on the Monte Carlo method to automatically improve the manually tuned multiple feedback control loops. Damage Equivalent Loads are quantified for minimising the cost function and automatically update the control parameters. The preliminary results presented here show the potential of this novel optimisation methodology to improve the mechanical fatigue loads of the desired components whereas maintaining the overall performance of the wind turbine system. This methodology provides a good balance between the computational complexity and result effectiveness. The study is carried out with the fully coupled non-linear NREL 5-MW wind turbine model mounted on the ITI Energy’s barge and the FASTv8 code. Full article
(This article belongs to the Special Issue Optimal Control of Hybrid Systems and Renewable Energies)
Show Figures

Graphical abstract

23 pages, 9828 KiB  
Article
Control of Hybrid Diesel/PV/Battery/Ultra-Capacitor Systems for Future Shipboard Microgrids
by Muhammad Umair Mutarraf, Yacine Terriche, Kamran Ali Khan Niazi, Fawad Khan, Juan C. Vasquez and Josep M. Guerrero
Energies 2019, 12(18), 3460; https://doi.org/10.3390/en12183460 - 7 Sep 2019
Cited by 28 | Viewed by 5558
Abstract
In recent times, concerns over fossil fuel consumption and severe environmental pollution have grabbed attention in marine vessels. The fast development in solar technology and the significant reduction in cost over the past decade have allowed the integration of solar technology in marine [...] Read more.
In recent times, concerns over fossil fuel consumption and severe environmental pollution have grabbed attention in marine vessels. The fast development in solar technology and the significant reduction in cost over the past decade have allowed the integration of solar technology in marine vessels. However, the highly intermittent nature of photovoltaic (PV) modules might cause instability in shipboard microgrids. Moreover, the penetration is much more in the case of utilizing PV panels on ships due to the continuous movement. This paper, therefore, presents a frequency sharing approach to smooth the effect of the highly intermittent nature of PV panels integrated with the shipboard microgrids. A hybrid system based on an ultra-capacitor and a lithium-ion battery is developed such that high power and short term fluctuations are catered by an ultra-capacitor, whereas long duration and high energy density fluctuations are catered by the lithium-ion battery. Further, in order to cater for the fluctuations caused by weather or variation in sea states, a battery energy storage system (BESS) is utilized in parallel to the dc-link capacitor using a buck-boost converter. Hence, to verify the dynamic behavior of the proposed approach, the model is designed in MATLAB/SIMULINK. The simulation results illustrate that the proposed model helps to smooth the fluctuations and to stabilize the DC bus voltage. Full article
(This article belongs to the Special Issue Optimal Control of Hybrid Systems and Renewable Energies)
Show Figures

Graphical abstract

22 pages, 2903 KiB  
Article
Hybrid Nonlinear MPC of a Solar Cooling Plant
by Eduardo F. Camacho, Antonio J. Gallego, Juan M. Escaño and Adolfo J. Sánchez
Energies 2019, 12(14), 2723; https://doi.org/10.3390/en12142723 - 16 Jul 2019
Cited by 12 | Viewed by 2765
Abstract
Solar energy for cooling systems has been widely used to fulfill the growing air conditioning demand. The advantage of this approach is based on the fact that the need of air conditioning is usually well correlated to solar radiation. These kinds of plants [...] Read more.
Solar energy for cooling systems has been widely used to fulfill the growing air conditioning demand. The advantage of this approach is based on the fact that the need of air conditioning is usually well correlated to solar radiation. These kinds of plants can work in different operation modes resulting on a hybrid system. The control approaches designed for this kind of plant have usually a twofold goal: (a) regulating the outlet temperature of the solar collector field and (b) choosing the operation mode. Since the operation mode is defined by a set of valve positions (discrete variables), the overall control problem is a nonlinear optimization problem which involves discrete and continuous variables. This problems are difficult to solve within the normal sampling times for control purposes (around 20–30 s). In this paper, a two layer control strategy is proposed. The first layer is a nonlinear model predictive controller for regulating the outlet temperature of the solar field. The second layer is a fuzzy algorithm which selects the adequate operation mode for the plant taken into account the operation conditions. The control strategy is tested on a model of the plant showing a proper performance. Full article
(This article belongs to the Special Issue Optimal Control of Hybrid Systems and Renewable Energies)
Show Figures

Figure 1

18 pages, 4516 KiB  
Article
A Firefly Algorithm Optimization-Based Equivalent Consumption Minimization Strategy for Fuel Cell Hybrid Light Rail Vehicle
by Han Zhang, Jibin Yang, Jiye Zhang, Pengyun Song and Xiaohui Xu
Energies 2019, 12(14), 2665; https://doi.org/10.3390/en12142665 - 11 Jul 2019
Cited by 17 | Viewed by 2933
Abstract
To coordinate multiple power sources properly, this paper presents an optimal control strategy for a fuel cell/battery/supercapacitor light rail vehicle. The proposed strategy, which uses the firefly algorithm to optimize the equivalent consumption minimization strategy, improves the drawback that the conventional equivalent consumption [...] Read more.
To coordinate multiple power sources properly, this paper presents an optimal control strategy for a fuel cell/battery/supercapacitor light rail vehicle. The proposed strategy, which uses the firefly algorithm to optimize the equivalent consumption minimization strategy, improves the drawback that the conventional equivalent consumption minimization strategy takes insufficient account of the global performance for the vehicle. Moreover, the strategy considers the difference between the two sets of optimized variables. The optimization objective is to minimize the daily operating cost of the vehicle, which includes the total fuel consumption, initial investment, and cycling costs of power sources. The selected case study is a 100% low-floor light rail vehicle. The advantages of the proposed strategy are investigated by comparison with the operating mode control, firefly algorithm-based operating mode control, and equivalent consumption minimization strategy. In contrast to other methods, the proposed strategy shows cost reductions of up to 39.62% (from operating mode control), 18.28% (from firefly algorithm-based operating mode control), and 13.81% (from equivalent consumption minimization strategy). In addition, the proposed strategy can reduce fuel consumption and increase the efficiency of the fuel cell system. Full article
(This article belongs to the Special Issue Optimal Control of Hybrid Systems and Renewable Energies)
Show Figures

Figure 1

Back to TopTop