Browsing by Author "Gonzalez Morales, Luis Gerardo"

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A data-driven forecasting strategy to predict continuous hourly energy demand in smart buildings
(2021) Duque Perez, Oscar
Smart buildings seek to have a balance between energy consumption and occupant com-fort. To make this possible, smart buildings need to be able to foresee sudden changes in the build-ing’s energy consumption. With the help of forecasting models, building energy management sys-tems, which are a fundamental part of smart buildings, know when sudden changes in the energy consumption pattern could occur. Currently, different forecasting methods use models that allow building energy management systems to forecast energy consumption. Due to this, it is increasingly necessary to have appropriate forecasting models to be able to maintain a balance between energy consumption and occupant comfort. The objective of this paper is to present an energy consumption forecasting strategy that allows hourly day-ahead predictions. The presented forecasting strategy is tested using real data from two buildings located in Valladolid, Spain. Different machine learning and deep learning models were used to analyze which could perform better with the proposed strategy. After establishing the performance of the models, a model was assembled using the mean of the prediction values of the top five models to obtain a model with better performance. © 2021 by the authors. Licensee MDPI, Basel, Switzerland
A review of I–V tracers for photovoltaic modules: topologies and challenges
(2021) Morales Aragonés, José Ignacio; Davila Sacoto, Miguel Alberto; Gonzalez Morales, Luis Gerardo; Alonso Gómez, Víctor; Gallardo Saavedra, Sara; Hernandez Callejo, Luis
ltage (I–V) curve tracers are used for measuring voltage and current in pho-tovoltaic (PV) modules. I–V curves allow identifying certain faults in the photovoltaic module, as well as quantifying the power performance of the device. I–V curve tracers are present in different topologies and configurations, by means of rheostats, capacitive loads, electronic loads, transistors, or by means of DC–DC converters. This article focuses on presenting all these configurations. The paper shows the electrical parameters to which the electronic elements of the equipment are exposed using LTSpice, facilitating the appropriate topology selection. Additionally, a comparison has been included between the different I–V tracers’ topologies, analyzing their advantages and disadvantages, considering different factors such as their flexibility, modularity, cost, precision, speed or rating, as well as the characteristics of the different DC–DC converters.
Análisis del impacto de la implementación de la tecnología V2G en redes de distribución eléctrica
(Universidad de Cuenca, 2021-04-14) Delgado Ávila, Erick Gabriel; Medina Muima, José Luis; Espinoza Abad, Juan Leonardo; Gonzalez Morales, Luis Gerardo
This document presents an analysis of the impact of V2G technology implementation in distribution networks, taking as reference an urban residential area of Cuenca, belonging to feeder 0324, owned by Empresa Eléctrica Regional Centrosur C.A. This study uses the software CYME / Cymdist. The analysis is focus on the distribution lines and distribution transformers load level, voltage levels, feeder demand, and feeder losses. For this, the use of the electric vehicle (EV) has been modeled and its main electrical parameters have been determined. The analysis is carried out based on 14 study scenarios, based on penetration level of EVs, behavior of electrical demand and type of EV. From the results obtained, it was possible to evaluate the behavior of the electrical network with V2G, and compare between the scenarios proposed
Análisis técnico sobre el comportamiento energético de un Autobús Eléctrico en recorridos en la ciudad de Cuenca
(2019-10-15) Carchi Tenesaca, Edisson Ermel; Peñafiel Garay, Darwin Anibal; Gonzalez Morales, Luis Gerardo
In this study, a technical analysis is carried out on the energy behavior of an electric bus on routes in the city of Cuenca - Ecuador, taking into account the data of the K9G electric bus of the company BYD. The study is focused on taking energy measurements delivered to the electric bus for charging its storage system, energy provided by the Centro Sur Regional Electric Company (CENTROSUR) and the Micro-networks laboratory of the University of Cuenca; In addition, the electrical behavior, energy supply provided by the regenerative braking and energy efficiency of the bus under study is verified. Another aspect presented in this work is related to the average distance traveled by the bus on the different commercial routes; for which an analysis of the aforementioned parameters was carried out including a comparison of energy efficiency and operating costs of the behavior of the electric bus versus internal combustion buses. In this sense, the analysis of the energy behavior and the use of the energy necessary for the daily bus load are the main topics addressed in this work. The study has laboratory and field activities that involve the characterization of the energy system supplied for charging the electric bus and the dynamic behavior it will have on the different routes. In addition to presenting a pilot study through the technique of data collection on the perception of users about the use of this type of public transport in the city.
Análisis técnico y económico para la implementación de sistemas de generación solar fotovoltaica para autoabastecimiento en la planta industrial y granja porcícola de la Empresa Italimentos CIA. LTDA
(Universidad de Cuenca, 2021-04-16) Aguilar Ramón, Jimmy Andrés; Illescas Barreto, Walter Sebastián; Espinoza Abad, Juan Leonardo; Gonzalez Morales, Luis Gerardo
This titling work presents the technical, economic, and environmental study that involves the implementation of photovoltaic solar generation systems grid connected, which are intended to self-supply the energy demand of two facilities belonging to the Italimentos limited company; the first, in the industrial plant located in Cuenca city, Azuay province and the second in the pig farm that is located near to Santa Rosa, El Oro province. As a starting point, Regulation No. ARCONEL 003/18, updated through Nro. ARCONEL- 057/18 resolution, issued by the Electricity Regulation and Control Agency, is analyzed, which, as of the date of publication of this document, is the one that establishes the conditions for the development, implementation and participation of regulated customers that have a photovoltaic solar generation system in Ecuador. Then, the characterization of the electricity demand in the study areas is carried out through measurements carried out with a specialized energy analyzer, trying to know the impact that the proposed systems may have on the company's areas. Subsequently, after defining the existing solar resource in the areas of interest, through local and international meteorological sources, the technical analysis is carried out for the implementation of the systems seeking to obtain the highest possible efficiency and performance considering parameters that influence in the characterization of solar photovoltaic energy production. Then, with the results obtained in the technical analysis, the initial investment cost estimate for the projects is made, taking as a reference detailed prices in updated international bibliographic sources, which will serve as a basis to determine the economic-financial viability evaluated under different financing scenarios. Finally, the fiscal and environmental benefits are exposed, with which the company can benefit when implementing projects that incentivize the use of renewable energies and energy efficiency
Análisis y modelado de baterías de Ion Litio para vehículos eléctricos
(2018) Pillco Valladolid, Franklin Medardo; Gonzalez Morales, Luis Gerardo
The present study analyzes the existing electrical models and identifies the one that best represents the actual behavior of Lithium Ion accumulators for electric vehicles. This document presents a bibliographical study on the typologies and background of electric vehicles. The technologies and the current trend of the electrochemical storage systems that are applied in the accumulators of electric vehicles are reviewed. The main characteristics of lithium ion batteries, their operation, internal processes and the main factors that degrade this type of accumulator are analyzed. The parametrization processes of the equivalent circuits that reproduce the behavior of the accumulator from an electric approach are reviewed. The study approach include the different equivalent circuits that reproduce the behavior of the accumulator, its main characteristics and its parameterization, to subsequently make the application of a model that characterizes the behavior of an accumulator module of the Kia Soul electric vehicle, owned by the University of Cuenca, and five models of equivalent circuits for two accumulator cells, which have applications in the electric traction. A characterization of the modeled cells for the energy requirements of the Kia Soul vehicle is carried out and also the validation of the modules proposed with the modeled cells is made when making a comparison with the model of the vehicle accumulator bank. Finally, an analysis of the results of the models is made with respect to the experimental data, of which different levels of accuracy are shown
Analysis of different energy storage technologies for microgrids energy management
(EDP Sciences, 2020) Gonzalez Morales, Luis Gerardo; Benavides Padilla, Dario Javier; Aguado Sánchez, José Antonio; Arévalo Cordero, Wilian Paul
The importance of energy storage systems is increasing in microgrids energy management. In this study, an analysis is carried out for different types of energy storage technologies commonly used in the energy storage systems of a microgrid, such as: lead acid batteries, lithium ion batteries, redox vanadium flux batteries and supercapacitors. In this work, it is analyzed the process of charging and discharging (slow and fast) in these systems, the calculation of energy efficiency, performance and energy supplied under different load levels, in its normal operating conditions and installed power capacity is developed. The results allow us to choose the optimal conditions of charge and discharge at different levels of reference power, analyzing the strengths and weaknesses of the characteristics of each storage system within a microgrid.
Analysis of the integration of drift detection methods in learning algorithms for electrical consumption forecasting in smart buildings
(2022) Mariano Hernández, Deyslen; Hernández Callejo, Luis; Solís, Martín; Zorita Lamadrid, Angel; Duque Perez, Oscar; Gonzalez Morales, Luis Gerardo; García, Felix Santos; Jaramillo Duque, Alvaro; Ospino Castro, Adalberto; Alonso Gómez, Victor; Hugo J., Bello
Buildings are currently among the largest consumers of electrical energy with considerable increases in CO2 emissions in recent years. Although there have been notable advances in energy efficiency, buildings still have great untapped savings potential. Within demand-side management, some tools have helped improve electricity consumption, such as energy forecast models. However, because most forecasting models are not focused on updating based on the changing nature of buildings, they do not help exploit the savings potential of buildings. Considering the aforementioned, the objective of this article is to analyze the integration of methods that can help forecasting models to better adapt to the changes that occur in the behavior of buildings, ensuring that these can be used as tools to enhance savings in buildings. For this study, active and passive change detection methods were considered to be integrators in the decision tree and deep learning models. The results show that constant retraining for the decision tree models, integrating change detection methods, helped them to better adapt to changes in the whole building’s electrical consumption. However, for deep learning models, this was not the case, as constant retraining with small volumes of data only worsened their performance. These results may lead to the option of using tree decision models in buildings where electricity consumption is constantly changing.
Analysis of the Response of L and LCL Filters in Controlled Rectifiers used in Wind Generator Systems with Permanent Magnet Synchronous Generators
(2018) Vidal, José; Carranza, Oscar; Rodríguez, Jaime; Gonzalez Morales, Luis Gerardo; Ortega, Rubén
This paper presents the comparative study of the response of a Controlled Rectifier in a wind power system with a synchronous permanent magnet generator when a L filter and a LCL filter are used between the generator and the rectifier. The Rectifier is modeled considering an L filter and an LCL filter. In addition, the PWM switch model is used to linearize the controlled rectifier and obtain the equivalent circuit at the operating point and the equivalent circuit at small signal. From the equivalent small signal circuit, the transfer functions of the rectifier are obtained. These transfer functions are used to implement rectifier control loops. One of the main advantages of using the switch model in the rectifier is that it allows the rectifier to be simulated without the control loops. This allows a comparison of the variables of the rectifier with different filter types, in this case, a L filter and a LCL filter. The Duty cycles are calculated …
Application of LPWAN Technologies Based on LoRa in the Monitoring of Water Sources of The Andean Wetlands
(Springer, 2022) Gonzalez Morales, Luis Gerardo; Gonzalez Morales, Luis Gerardo
This paper presents the design of a water source monitoring system based on LoRa technology for the Tres Lagunas Andean high-altitude wetlands ecosystem (Ecuador). The solution has been implemented using mainly an ATmega1284p microcontroller, an SX1278 transceiver and hydrological sensors. The data is transmitted from the study site to the TTN server and sent via the MQTT protocol to the Node-RED platform. On the other hand, a graphical interface has been developed that allows analyzing historical data of temperature, dissolved oxygen (DO), oxidation-reduction potential (ORP) and hydrogen potential (pH). Furthermore, energy consumption tests and LoRa physical layer experiments have been performed with the prototype. Results reveal the proper operation of the prototype. In particular, it has been observed that SF9 and SF10 present packet reception rates higher than 97%. Regarding SF7 and SF8, they was discarded for this type of scenarios due to the packet loss rate higher than 10%. The main contribution of this work is the proposal of a portable, low-cost and open source prototype, focused on the transmission of hydrological data obtained in Andean high-altitude lakes through IoT technologies for the administration, management and control of water resources that represent a fundamental component of a smart city.
Charge management of electric vehicles from undesired dynamics in solar photovoltaic generation
(2022) Zorita Lamadrid, Ángel Luis; Davila Sacoto, Miguel Alberto; Gonzalez Morales, Luis Gerardo; Aguirre Pardo, Ivania Carolina; Duque Pérez, Óscar; Hernández Callejo, Luis; Espinoza Abad, Juan Leonardo
Power generation from photovoltaic solar systems contributes to mitigate the problem of climate change. However, the intermittency of solar radiation affects power quality and causes instability in power grids connected to these systems. This paper evaluates the dynamic behavior of solar radiation in an Andean city, which presents rapid power variations that can reach an average of 7.20 kW/min and a variability coefficient of 32.09%. The study applies the ramp-rate control technique to reduce power fluctuations at the point of common coupling (PCC), with the incorporation of an energy storage system. Electric vehicle batteries were used as the storage system due to their high storage capacity and contribution to power system flexibility. The application of the control strategy shows that, with a minimum of five electric vehicle charging stations at the PCC, the rate of change of the photovoltaic can be reduced by 14%.
Comparación de modelos de seguimiento solar y análisis económico-eléctrico de un sistema solar fijo
(Universidad de Cuenca, 2021-08-11) Carpio Vintimilla, Javier Fernando; Gonzalez Morales, Luis Gerardo
The environmental damage caused by the use of fossil fuels has increased substantially on the planet, this drives initiatives that promote the use of new non-conventional renewable energy sources, in this case photovoltaic solar energy. This is a clean energy because it does not produce environmental pollution and sustainable because the solar resource is present all the time on our planet. The present work seeks to analyze the generation of electricity through photovoltaic solar energy, comparing three different systems. For this purpose, three small-scale prototypes of solar energy collection are analyzed through simulations and measurements, which are: the conventional fixed system with a panel taking data in a single geographical position all the time, secondly, a solar tracker of one axis (from east to west) and finally a tracker of all cardinal points (two axes) is added, to analyze through results the best solar photovoltaic system. Complementarily, an electrical and economic analysis of the photovoltaic system of the Balzay Campus of the University of Cuenca is carried out to determine the feasibility of executing studies of solar photovoltaic micro generation projects considering the regulations of the public service of electric energy in force in Ecuador, both for companies and conventional houses in the city of Cuenca. In addition, a small survey is conducted to determine what economic value people would be willing to pay for a clean electricity service
Comparative study of continuous hourly energy consumption forecasting strategies with small data sets to support demand management decisions in buildings
(2022) Hernández Deyslen, Mariano
Buildings are one of the largest consumers of electrical energy, making it important to develop different strategies to help to reduce electricity consumption. Building energy consumption forecasting strategies are widely used to support demand management decisions, but these strategies require large data sets to achieve an accurate electric consumption forecast, so they are not commonly used for buildings with a short history of record keeping. Based on this, the objective of this study is to determine, through continuous hourly electricity consumption forecasting strategies, the amount of data needed to achieve an accurate forecast. The proposed forecasting strategies were evaluated with Random Forest, eXtreme Gradient Boost, Convolutional Neural Network, and Temporal Convolutional Network algorithms using 4 years of electricity consumption data from two buildings located on the campus of the University of Valladolid. For performance evaluation, two scenarios were proposed for each of the proposed forecasting strategies. The results showed that for forecasting horizons of 1 week, it was possible to obtain a mean absolute percentage error (MAPE) below 7% for Building 1 and a MAPE below 10% for Building 2 with 6 months of data, while for a forecast horizon of 1 month, it was possible to obtain a MAPE below 10% for Building 1 and below 11% for Building 2 with 10 months of data. However, if the distribution of the data captured in the buildings does not undergo sudden changes, the decision tree algorithms obtain better results. However, if there are sudden changes, deep learning algorithms are a better choice
Control de frecuencia mediante gestión de demanda durante el proceso de carga lenta en vehículos eléctricos
(Universidad de Cuenca, 2020-06-15) Maldonado Pineda, Erika Lisbeth; Gonzalez Morales, Luis Gerardo
Around the world, Climate Change has driven a growing trend in the use of renewable energies. Within the set of initiatives to reduce carbon emissions, the use of electric vehicles plays an important role, because they can deliver zero emission of polluting gases and they promote the development of renewable energy sources which are necessary to recharge their batteries. Ecuador, due to its geographical characteristics and specially by its water resources, has a capacity to generate enough electricity to cover the country’s current demand, therefore this is a convenient region to support the introduction of EVs. Although the use of electric vehicles brings great advantages in terms of reducing environmental impacts, it is necessary to take into account the potential problems that their mass introduction will cause in the country’s electricity grid, where an expected result would be the high demand for power consumption during peak hours. Thus, next work focuses on the analysis and development of a primary frequency regulation algorithm during the slow charging process of electric vehicles. The proposed algorithm aims to help reduce the generation/demand difference which would allow maintaining the quality of the electricity grid within the ranges established by the CONELEC. The slow charging station used for this work operates with a maximum power of 4.8kW, but is possible to reduce it according of the grid’s features and the vehicule which is charging at the same time, such as reductions in the frequency due to overloads in the grid. At this point is where the primary frequency control comes into play,in this research the frequency measurement algorithm known as Fast Fourier Transform is used, which was implemented in an Arduino Due and whose response allows modifying the load reference sent to the electric vehicle. Experimental tests for this thesis were carried out in the Balzay Micro grid Laboratory of the University of Cuenca, which has the necessary equipment for its development. The implementation of the algorithm exhibit positive results, since the decrease in power consumption of the electric vehicle took place within the established ranges, where for every 0.3 Hz reduced in the frequency of electricity grid, power consumption of the electric vehicle was reduced 12.5 %. In addition, the response time that the algorithm requires to reduce the power consumption was measured, which is 10 seconds and this is within the operating range of the primary frequency control
Degradation analysis of 5-year field exposed photovoltaic modules using low-cost thermography, electroluminescence and I-V curve tests in Ecuador
(Institute of Electrical and Electronics Engineers Inc., 2020) Espinoza Abad, Juan Leonardo; Dávila Sacoto, M.A.; Hernández Callejo, Luis; Gonzalez Morales, Luis Gerardo; Espinoza Abad, Juan Leonardo
Detection of degradation of photovoltaic (PV) modules is important for the maintenance and operation of solar PV farms to reduce production losses. Infrarred (IR) Thermography, Electroluminescence (EL) and I-V curve tracers are detection techniques that generally use high-cost equipment, which limits their use in developing countries due to the tight budgets they manage for research and development. This study shows the use of low-cost alternatives to determine the deterioration of 140 solar PV modules at the University of Cuenca-Ecuador. This array has functioned continually without fail for 5 years. Measurement equipment for degradation detection techniques with a cost of less than 1, 000.00USD is used and its application is validated with professional equipment. A power loss of 1.29% per year is obtained. In addition, the use of degradation values obtained from similar studies is proposed to reduce the effort of detecting deterioration modes, whose approximation allows the calculation of the power delivered by the installation with a 2.04% error. A method for the economic quantification due to the losses caused by the deterioration of solar PV modules is also exposed.
Desarrollo de una metodología para la ubicación de estaciones de carga de vehículos eléctricos, caso de estudio: ruta Cuenca–Guayaquil
(Universidad de Cuenca, 2020-10-12) Paute Torres, Jorge Andrés; Sempértegui Moscoso, María Emilia; Gonzalez Morales, Luis Gerardo; Espinoza Abad, Juan Leonardo
In this work, the authors present a methodology to identify the location of fast charging stations for electric vehicles at interprovincial and/or intercantonal routes, using a mathematical model of a vehicle‘s energy consumption and based on various criteria that each potential location must comply for its final selection. In chapter 2, there is a review about electric vehicles, types of battery technologies, charging modes and types of connectors, among other topics. Subsequently, chapter 3 develops the study of a "quasi-stationary backward" mathematical model to estimate the energy consumption of an electric vehicle based on the dynamic behavior of a moving car on a road’s surface. Chapter 4 shows the procedure used for data acquisition with a vehicle using geolocation equipment and the vehicle's on-board computer. In addition, a mathematical model implementation and its calibration are carried on Matlab, as well as the validation through three test routes. Chapter 5 presents the methodological process developed to obtain the location of the fast charging station on the Cuenca - Guayaquil route via Colectora Cuenca – Puerto Inca (E582), using the proposed mathematical model on chapter 4. Chapter 6 explains the behavior of the PNE Solution 50 kW fast charging station and its impact on the quality of electrical energy, taking as reference Regulation No. ARCONEL 005/18.
Desarrollo de una simulación para el control de una estación de carga modo 3 en CA para vehículos eléctricos
(Universidad de Cuenca, 2021-03-24) Llivicura Arias, David Alfredo; Torres Aguilar, Frank Leonel; Gonzalez Morales, Luis Gerardo
This work covers a modeling of a mode 3 charging station control system under the IEC 61851-1 standard in alternating current for electric vehicles. The simulation makes use of free software tools, the communication process of the charging station with the electric vehicle is simulated in order to charge its batteries, the simulation also presents a validation and payment system to users who wish charge your electric vehicle using RFID technology and through a graphical interface. All the information about each recharge made will be stored on a free web server on the Internet and also on a local server as a backup method in case the station does not have a place that does not have Internet access. It is worth mentioning that this server will have a database to support all the necessary information such as load history that have been made in the station. The web server on the Internet will be based on the protocol that charging stations currently have known as OCPP, the web server will have an interface so that users can access their personal information, as well as charging history, balance, search for a charging station. available load in a given geographic area, ability to manage multiple stations, data validation to allow transactions, real-time information display in web browsers, card and transaction management. After the simulation process, a mode 3 charging station prototype was made under the IEC 61851-1 standard at 43 kW, the infrastructure of the charging station allows it to be located in public places. As safety elements, the station has an emergency button to stop EV charging, ground connections for the entire electrical system and a differential switch. The infrastructure of the station also allows it to be scalable, that is to say that in the future another charging system can be placed with its respective charging connector and thus charge two electric vehicles simultaneously. A study of charging infrastructures is carried out in mode 3, which are commonly referred to as semi-fast charging stations in AC under the IEC 61851-1 standard, while fast charging stations, which work in DC, are grouped under mode 4 of IEC 61851-23. To provide security to the station, several cases were simulated in which unsafe conditions could occur when charging the electric vehicle. Finally, a communication protocol is implemented between the charging station and a server, similar to the OCPP communication protocol, stored in the application platform as a Heroku service. This server has the capacity to manage multiple stations, data validation to allow transactions, display of information in real time in web browsers and data management such as users, cards, transactions, etc.
Design and analysis of performance and power quality of a led driver
(Institute of Electrical and Electronics Engineers Inc., 2018) Gonzalez Morales, Luis Gerardo
This paper presents the design of a driver for 6 W residential LED luminaries with a Flyback topology in discontinuous conduction mode (DCM) using the FT833B12 integrated circuit, which has a constant current control without a feedback circuit. The built prototype is compared to a pair of similar commercial drivers where the characteristics of energy efficiency and current distortion are improved until achieving an efficiency of approximately 82% and harmonic distortion of 93.18%. Using a computational tool and considering the main losses of the built prototype, a study of the performance of the prototype is made.
Design and analysis of performance of a forward converter with winding tertiary
(Institute of Electrical and Electronics Engineers Inc., 2018) Gonzalez Morales, Luis Gerardo
In this paper, the design and performance analysis of a Forward converter with third winding is presented. It establishes performance comparisons of simulation tools, analysis of losses and experimental measurements at different points of operation. It details a performance analysis obtaining the most important losses in the energy processing, operating in the continuous conduction mode (CCM), the nominal power of the prototype is 12 W. The converter has a voltage control system in order to maintain the output voltage constant against load and input voltage disturbances.
Design and evaluation of an energy management system applied to a lower limb robotic exoskeleton
(2021) Zhang, Huiyan
This paper presents the design, development and evaluation of an energy management system (EMS) for covering the energy demand from an autonomous lower limb exoskeleton (ALLEX) prototype. The ALLEX prototype is composed by four energy subsystems: actuators, sensing, communications, and control. The energy de-manded by ALLEX is estimated by considering metabolic requirements of neurological rehabilitation applied to the actuators subsystem, as well as average consumption of the sensing, communications, and control subsystems. The EMS proposed in this paper is composed by a lithium-ion battery bank, a battery management system (BMS), and prop-er instrumentation for measuring voltages, currents, and temperature from the battery pack. Experimental results show adequate coverage of the energy demand from ALLEX, both instantly and during continuous operation (1 hour approximately). Additionally, the efficiency of the EMS is assessed by testing the cells balancing and battery charg-ing/discharging processes, which showed equalized values of the energy cells as well as correct temperature operating values