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This study comprehensively examines the techno-economic potential of utilizing offshore wind resources for hydrogen production in Mexico. Through the integration of geospatial analysis techniques with energy generation and economic models, the research estimates hydrogen production, CO 2 eq emissions reduction potential, Levelized cost of electricity (LCOE), and Levelized cost of hydrogen (LCOH). The analysis highlights Mexico's capacity to produce up to 217.33 million tons of hydrogen annually, predominantly from the Gulf of Mexico. Centralized offshore hydrogen production demonstrates significant cost advantages, being up to 0.92 USD/kg cheaper than onshore production. The study also underscores the economic benefits of repurposing existing oil and gas infrastructure, which can reduce LCOH by up to 11%. Environmental benefits are substantial, with hydrogen use in ammonia production potentially reducing CO 2 eq emissions by 82.5%. Additionally, the study identifies highly suitable offshore areas for hydrogen production, particularly near existing oil infrastructure, facilitating the integration of new renewable energy projects with minimal additional infrastructure development. These findings provide valuable insights for policymakers and stakeholders, emphasizing the economic viability and environmental benefits of offshore wind hydrogen production as a strategic pathway for Mexico's energy transition and decarbonization efforts. [Display omitted] • Mexico can produce 217.33 MTon/year of hydrogen, 78.8% from the Gulf. • Transmitting energy offshore and then producing H 2 is up to 0.92 USD/kg cheaper. • Repurposing offshore oil infrastructure reduces LCOH by up to 11%. • 40% of offshore areas, near oil infrastructure, are ideal for hydrogen production. • 82.5% of CO 2 eq emissions in ammonia production could be reduced. [ABSTRACT FROM AUTHOR]

In the quest for sustainable energy solutions in developing nations, this investigation leverages advanced geospatial analysis to explore the expansive potential for offshore wind energy within Mexico's Exclusive Economic Zone (EEZ). By meticulously accounting for geographic and depth-related constraints, the study assesses the feasibility of implementing both fixed-bottom and floating wind energy technologies. Revealing an offshore wind capacity of 1,609.7 GW, capable of producing an estimated 12,688 TWh annually, our analysis highlights the capacity to exceed Mexico's current energy consumption by thirty-three-fold. Significantly, it determines that 58% of the evaluated maritime area is suitable for floating technologies, while 42% could support fixed-bottom installations. Economic evaluations, including the Levelized Cost of Energy (LCOE) analysis, suggest a competitive price range of 63 to 241 USD/MWh, positioning offshore wind as a viable alternative to conventional and hydroelectric power sources. Although the study identifies considerable potential, it also exposes significant infrastructural challenges in Mexico's electrical grid, which pose barriers to the effortless integration of offshore wind technology. The findings underscore the urgent need for infrastructural improvements and strategic policy modifications to maximize the use of Mexico's plentiful offshore wind resources. Additionally, the research stresses the critical role of international cooperation, through North-South partnerships, in expediting the shift toward renewable energy sources. [Display omitted] • Mexico's offshore maximum capacity is 1,609.7 GW. • Floating technology is viable in 58% of the suitable area; 42% is suitable for fixed-bottom installations. • Only 2.3% of offshore wind energy would be needed for transport electrification. • LCOE ranges from 63 to 241 USD/MWh, making it competitive in the North American market. [ABSTRACT FROM AUTHOR]

Many efforts have been made to assess the potential of green hydrogen production at global, regional, and national levels using Geographic Information Systems (GIS); however, many dismiss the possibility of producing hydrogen in urban settlements. In order to reveal the true potential of these areas, it is essential to provide arguments that allow evaluation of the feasibility of promoting and impulsing the concept of hydrogen cities. Based on this idea, this work assesses the monthly and annual potential of solar hydrogen in urban areas of Mexico using actual measurements of sunshine duration as electrolyzer production times. Moreover, as light transportation is crucial for cities, we examine the substitution of gasoline with hydrogen and its cost throughout the year. These constitute the main contribution of the present work. This study departs from the geographical and technical potential of solar energy, and by using GIS, the amount of hydrogen production per unit of area (Ton/(km2 year)) was computed. The levelized cost of hydrogen production (LCOH) is also evaluated, using two of the most popular and commercial electrolysis technologies: PEM and Alkaline. Our results revealed that Mexican urban areas have a high potential to produce solar hydrogen, having an average annual production that varies from 1991.8 Ton/km2 to 4338.3 Ton/km2 according to the region. The total solar hydrogen potential of all Mexican urban places is 9.39 MTon/year, which could satisfy up to 42.6 times the 2020 hydrogen demand of Mexico. We found that the national gasoline consumption could be replaced by H 2 , requiring between 42% and 52% of the total urban production. Additionally, the national average of LCOH was found to be about 6.25 USD/kg for alkaline electrolyzer and 9.50 USD/kg for PEM technology, considering the yearly average sunshine duration of 3237 h/year, which means that Mexico could be competitive at large-scale hydrogen production by using Alkaline technology. Our findings have the potential to impact positively on the country since they provide information to facilitate the derivation of public policies from a rigorous and technical perspective. [Display omitted] • Urban hydrogen potential could satisfy up to 42.6 times the 2020 Mexico's hydrogen demand. • Light transportation would require between 46.1% and 54.7% of the total hydrogen produced. • Spring and summer had the largest production, between 0.52 MTon/month and 0.81 MTon/month. • LCOH was estimated to be between 6.25 USD/kg and 9.50 USD/kg for Alkaline and PEM technologies. • Alkaline electrolyzers resulted in a more feasible technology in the short term. [ABSTRACT FROM AUTHOR]

The effect of the energy interchange dynamics on the Zero-Energy Hydrogen Economy (ZEH2E) of households with Fuel-cell Hybrid Electric Vehicles (FCHEV) is investigated in this work. An isolated grid constituted of a household, a battery bank, a PEMFC, a PEM electrolyzer, and PV panels were used as a rig for the study together with an optimal energy management strategy, which guaranteed ≥100% PV self-sufficiency index of the household load and hydrogen harvesting for electrical transportation. Global horizontal irradiance and temperature data, measured every 10 min for 365 days in three different locations of Mexico and Hardware-in-the-loop experiments were used in the analysis. Short and long-term effects of the energy storage system and their importance for achieving ZEH2E conditions were identified. Proposed solar, and battery utilization indexes revealed the short-term effect of the battery storage, imperceptible even in daily average values. Hydrogen production and vehicle autonomy values strongly depended on the season of the year, location, vehicle characteristics, driving cycle, and household load, therefore two indexes were proposed to compare the different scenarios: the hydrogen production-to - average household power load ratio (m H 2 -to-load) and the average vehicle power per traveled distance. These indexes allowed us to reveal low effective load-location pairs for hydrogen production and low effective driving cycle-vehicle pairs for hydrogen utilization. Our results revealed that the average data to analyze ZEH2E conditions is not enough and that detailed data is necessary. [Display omitted] • The effect of the energy dynamics on ZEH2E of households with FCHEV is studied. • Hardware-in-the-Loop experiments as well as real solar irradiance and temperature data are used. • 3 locations, 2 household electric load profiles, 4 vehicle types are tested. • Proposed indexes revealed short-term and long-term actions of the energy sources. • 0.36–1 g of H 2 per load power were found and autonomy values from 52 to 116 km per day. [ABSTRACT FROM AUTHOR]

Abstract The problem of optimal power management for uncertain off-grid hybrid systems is studied in this paper. A suitable parametrization of the energy sources and sinks is used to obtain a graphical representation of the feasible set along with a direct observation of the solution and its piecewise description. The proposed approach pretends to clarify how the optimal solution migrates from the use of one source to another as the solar radiation changes and how the dynamic response of the sources restrict the feasible set. A power generation system (PGS) is used to study the limitations that the sun power variability and the parametric uncertainty impose on the optimality; being the PGS constituted by photovoltaic (PV) panels, a fuel cell (FC), an electrolyzer (E) and a battery bank. A simple optimal Power Management Strategy (PMS) is proposed as a result of the analysis and its performance is illustrated in a telecom facility for three different locations in Mexico. Results are shown indicating the viability of the strategy for highly variable environments. Highlights • A graphical approach for optimal power management is proposed. • A parametrization is used to allow simplification of the optimization problem. • The case of parameter uncertainty in the power hybrid system is analyzed. • Results demonstrate that optimal operation is possible in presence of uncertainty. [ABSTRACT FROM AUTHOR]

This paper introduces a means to evaluate the severity of the lateral skid phenomenon based on a balance of forces applied to the vehicle. Derived from this analysis, a lateral Skid Index (SI) is proposed which, along with the well-known rollover index, is used to monitor the vehicle and to derive an indirect envelope specification. A robust control ensures the accident risk mitigation in spite of model uncertainty and perturbations from the driver. Speed and predictive dependent risk switching criteria are used to activate the control action. The proposed strategy is illustrated using Hardware-in-the-Loop experiments and its comparison with existing strategies is performed. [ABSTRACT FROM AUTHOR]

In this paper, it is proven that a state dependent switching law designed for integrator switched systems can be used to stabilize complex switched uncertain nonlinear systems as well as a class of impulsive systems, provided that the upper bound of the uncertainty terms satisfy a relationship with the nominal system parameters estimation of the nominal system parameters. In order to establish such a result, firstly, a switching law is proposed to ε -practically stabilize an uncertain integrator switched system; secondly, the proposed switching law is used to prove that the trajectories of a general class of uncertain nonlinear systems are ε -practical stable and connections to switched nonlinear impulsive systems are revealed. Numerical simulations allow us to illustrate the proposed stability results and an example in a power electronics device is used to show the applicability of the proposed state-dependent switching control strategy. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, the geometry and operation of membraneless laminar flow-based fuel-cells (LFFC) is analyzed. Three different fuel cell geometries are studied, these are: the conventional rectangular cell, a cylindrical cell and a star shaped cell. The geometries are derived from the principle of design of increasing the effective area of cathode while conserving the same volume-to-length ratio. Since the mixing and depletion widths are major factors that determine the cell performance, maximum Reynolds and Péclet numbers as well as fuel utilization are considered as variables of comparison. Furthermore, electrical characteristics as current density and total extracted current have been considered as well. Using finite element simulations, it is shown that for a HCOOH−O2 cell, improved fuel utilization of 89% and 68.2% can be obtained with star and cylindrical geometries respectively, in comparison to conventional rectangular geometry (42.4%). Moreover, the total extracted current is also improved, reaching percentages greater than 1200% and 400% for the star and cylindrical designs respectively. It is shown that moving liquid–liquid interface, it is possible to further increase the current density of the designs and therefore the total extracted current. [Copyright &y& Elsevier]

Abstract: This paper presents the design of a flexible analog signal conditioning circuit (SCC) able to be reconfigured de- pending on user requirements. The SCC can be employed with DSP-based systems. The design is aimed to be used in power electronics applications where a wide range of signals types are present. In order to guarantee reconfiguration, the design is constituted of interconnected stages that can be activated depending on the characteristics of the input signal. The proposed circuit is a simple and a low cost solution because it employs off-the-shelf components. [Copyright &y& Elsevier]

Abstract: An excitation controller for a single generator based on modern multi-loop design methodology is presented in this paper. The proposed controller consists of two-loops: a stabilizing (damping injection) loop and a voltage regulating loop. The task of the stabilizing loop is to add damping in the face of voltage oscillations. The voltage regulating loop is basically a PI compensator whose objective is to obtain terminal voltage regulation about the prescribed reference. The main contribution of this paper is to give some insights into the systematic derivation of multi-loop controllers of power generators. Certain connections between the two-loop excitation controller and standard PSS–AVR schemes are discussed. In this way, some insight into the stability of the standard PSS scheme is obtained from the analysis of the proposed controller. The proposed controller is evaluated via numerical simulations on a full finite-element model. [Copyright &y& Elsevier]

Abstract: The aim of this paper is to explore the application of detrended fluctuation analysis (DFA) to study roughness features of images. Unidimensional sequences at different image orientations are extracted and their average scaling exponent is estimated. In this form, the existence of anisotropies can be detected when considerable variations in the scaling exponent at different image orientation are observed. Different images from grass to solar granulation are analyzed and the underlying physics of such results is briefly commented. [Copyright &y& Elsevier]

The design and tuning of power system stabilizers (PSS) and automatic voltage regulators (AVR) of synchronous generators is usually performed using low-order two-axis models. Remarkable robust characteristics and systematic construction can be obtained with the recent developments on linear and nonlinear control theory. However, the properties and performance of the control designs are also evaluated using low-order equivalent-circuit models because large synchronous machines are not readily available to designers and researches. This may lead to doubts about the controller behavior under true operating conditions. The main objective of this work is to show that robust control designs, obtained with small order models, keep their good performance characteristics when applied to the actual machine. In order to circumvent the lack of the real machine, a very detailed finite-element model is developed to represent turbine generators connected to large power systems. The numerical model incorporates simulation of rotor motion, iron magnetic nonlinearity and eddy currents in the solid rotors of turbine generators. The control design is performed using constructive nonlinear control, which gives a systematic controller construction coupled to a simple tuning scheme. [Copyright &y& Elsevier]

This paper addresses the position regulation problem of robot manipulators under control input constraints. It is proven that the robot system under a saturated linear PID control is semiglobally asymptotically stable, if the torque bounds are larger than gravitational torques, and if the proportional gain is large enough and the integral gain is small enough.The stability analysis makes use of singular perturbation tools and the results are illustrated via numerical simulations. [Copyright &y& Elsevier]

Abstract This paper proposes a switching control strategy (SCS) for a bidirectional DC/DC converter. The aim of this strategy is managing the power that an ultra-capacitor (UC) has to deliver or absorb following a power reference required by the driving cycle ECE-15 of an electric vehicle (EV). For that purpose, the converter is modelled as a switched linear system. Based on hysteresis and logic switching, a switching rule is designed. Necessary and sufficient conditions for the existence of the switching rule are established. Simulation and experimental results of a 1 kW converter are shown to demonstrate the feasibility of this strategy. Highlights • A switching rule for a bidirectional DC/DC power converter for an EV is designed. • Switching rule is based on existence conditions of practical stabilizability. • Switching rule avoids the discontinuous conduction mode of the power converter. • Scale-down power consumption using a driving cycle ECE-15 was used for tests. • Inductor current tracking is achieved in one switching period. [ABSTRACT FROM AUTHOR]

This paper analyzes the stability and switching controllability properties of a single-phase PWM rectifier and its relationship with parameter uncertainty. Based on this analysis, a switching control strategy is proposed that has as objectives (i) to achieve input current tracking and low current THD (total harmonic distortion) as well as (ii) to regulate the output voltage in spite of perturbations. The proposed control does not require a PWM generation step design. Numerical simulations and experimental tests in a 1 kW prototype demonstrate the effectiveness of the proposed controller and illustrate the limits of system's controllability. [ABSTRACT FROM AUTHOR]