Abstract: This paper presents a methodology, based on frequency response models, to estimate the minimum or maximum value -nadir- that the frequency reaches when a generation - load unbalance occurs in the power system. To this end, the 1st order reduced equivalent model of the generator’s power-frequency control system is determined using the "Parameter Estimator" of Matlab/Simulink. Then, a set of equations coming from the reduced equivalent model is established to estimate the value of the maximum transient frequency deviation and its occurrence time. To illustrate the application of the proposed methodology, the IEEE New England test system has been chosen. Once this is done, the proposed methodology is applied to the Ecuadorian Interconnected Power System. The results of time domain simulations using the PowerFactory software are presented and compared with the results calculated using the developed reduced and analytical models. It is concluded that the proposed methodology estimates with high accuracy the maximum transient frequency deviation and its time of occurrence.

Resumen: En el presente trabajo se presenta una metodología, basada en modelos de repuesta de la frecuencia, para estimar el valor mínimo o máximo -nadir- que alcanza la frecuencia cuando en el sistema eléctrico de potencia se presenta un desbalance generación - carga. Con este fin, se determina el modelo reducido de 1er orden del sistema de control potencia - frecuencia del generador usando el “Estimador de Parámetros” de Matlab/Simulink. Luego, se establecen ecuaciones que provienen del modelo equivalente reducido para estimar el valor de la máxima desviación transitoria de la frecuencia y su tiempo de ocurrencia. Para ilustrar la aplicación de la metodología presentada se ha elegido el sistema de prueba IEEE New England de 39 barras y 10 generadores. Hecho esto, la metodología propuesta se aplica al Sistema Nacional Interconectado ecuatoriano. Se presentan resultados de simulaciones en el dominio del tiempo usando el programa PowerFactory, mismos que son comparados con los resultados calculados mediante el modelo equivalente reducido y el modelo analítico. Se concluye que la metodología propuesta estima con alta precisión la máxima desviación transitoria de la frecuencia y su tiempo de ocurrencia.

Direct current flow through power transformers in HVDC systems can lead to significant half-cycle saturation issues, putting the power system at risk. The HVDC system can function in monopolar ground return and unbalanced bipolar without earth return conductors. During these two HVDC modes of operation, a substantial direct current flows through the HVDC ground terminals, creating a ground DC potential difference between the neutrally grounded transformers. As a result, DC flows through the neutrals into the transformer windings. The study presents a transformer-neutral DC compensating device incorporating a novel control to solve the issue. Using a proper control strategy, injecting reverse DC into the grounding grid can compensate for direct current flow in transformer windings to mitigate the biased operating flux of power transformers. In this article, an in-depth analysis of transformer response to DC bias was investigated. Then, an Interval type-II fuzzy logic control (IT2FLC) was proposed as an effective control strategy for managing the neutral DC compensating system. Its robustness was assessed and analysed by comparing it with type-I fuzzy logic-based (T1FLC) and a PI-based compensation system. The control performance is examined using MATLAB/Simulink models and validated with rapid control prototype tests conducted with a SpeedgoatTM real-time target machine, assessing the transient response, oscillations, and settling time of the compensation device under DC bias voltage variations. The outcomes indicate that the IT2FLC controls the compensation device more effectively than other controllers to mitigate half-cycle saturation. This approach introduces a novel strategy to prevent transformer half-cycle saturation.

Abstract: The present work focuses on the optimization of maximum power tracking (MPPT) in photovoltaic systems by employing a new technique based on linear regression. The main purpose is to develop an MPPT algorithm using linear regression techniques, which involves identifying and tracking the maximum power point of solar panels more accurately. The proposed algorithm is developed in MATLAB/Simulink software and validated through experimental tests. Subsequently, the application of the algorithm is extended to an electrical network modeled and simulated in HYPERSIM software, this tool allows a more detailed analysis of the instantaneous dynamics of electrical and control variables in complex systems when varying factors such as temperature and irradiation. The innovative contribution of this work is not only limited to the improvement of MPPT algorithms in photovoltaic systems. It is highlighted that, although the term MPPT is mainly associated with solar PV, the optimization of available power is also relevant for other renewable energy sources. Optimizing the conversion of solar energy into usable electricity not only increases the cost-effectiveness and sustainability of these systems, but also highlights the key role in the transition to a more sustainable electricity supply. Abstract (MPPT techniques accurately MATLABSimulink MATLAB Simulink tests Subsequently irradiation that PV sources costeffectiveness cost effectiveness supply

Resumen: El presente trabajo se enfoca en la optimización del seguimiento de máxima potencia (MPPT) en sistemas fotovoltaicos mediante el empleo de una nueva técnica basada en regresión lineal. El propósito principal es desarrollar un algoritmo de MPPT que utilice técnicas de regresión lineal, lo que implica identificar y seguir con mayor exactitud el punto de máxima potencia de los paneles solares. El algoritmo propuesto se desarrolla en el software MATLAB/Simulink, validándose a través de pruebas experimentales. Posteriormente, se extiende la aplicación del algoritmo a una red eléctrica modelada y simulada en el software HYPERSIM, esta herramienta permite un análisis más detallado de la dinámica instantánea de las variables eléctricas y de control en sistemas complejos al variar factores como la temperatura e irradiación. La contribución innovadora de este trabajo no solo se circunscribe a la mejora de los algoritmos de MPPT en sistemas fotovoltaicos. Se destaca que, aunque el término MPPT se asocie principalmente con la energía solar fotovoltaica, la optimización de la potencia disponible también es relevante para otras fuentes de energía renovable. La optimización de la conversión de energía solar en electricidad utilizable no solo aumenta la rentabilidad y sostenibilidad de estos sistemas, sino que también destaca el papel fundamental en la transición hacia un suministro eléctrico más sostenible. Resumen (MPPT lineal solares MATLABSimulink MATLAB Simulink MATLAB/Simulink experimentales Posteriormente HYPERSIM irradiación fotovoltaica renovable sostenible

Abstract In this paper, an assessment of the state of coastal territories of Ecuador monitoring issue is conducted. The use of an autonomous robotic aerial platform is proposed as a technical solution to enhance the efficiency of remote surveillance missions performed by national security services along coastline. Considering the UAV nonlinear flight dynamics, as well as the missing information of the environment, is designed a UAV hierarchical control structure composed of an adaptive PID based MPC control strategy. The implementation of an adaptive PID based MPC controller leads to significantly improve the UAV optimal trajectory tracking task, as well as satisfy properties such as adaptiveness, self-learning, and capability of handling uncertainties caused by the unpredictable behavior of sea currents and wind loads retaining robust performance features. In this work, the investigation of external disturbances on UAV stabilization and positioning accuracy considers swirling wind flows and short-term wind gusts. These correspond to deterministic and random processes, are mathematically represented as trigonometric functions with random amplitudes determined by the gust coefficients and the wind loading periods of the pulses. The established range is given by a set of several observations of wind loads in the coastal territories of Ecuador. The analyzed data is collected from the database of national meteorological stations. Finally, the simulation process of the perturbed controlled motion of the UAV along a segmented linear trajectory, as well as the data analysis and graphics are carried out in the MATLAB environment.

Resumen En este trabajo se realiza una evaluación del estado de los territorios costeros del Ecuador en términos de monitoreo. El uso de una plataforma aérea robótica autónoma se propone como una solución técnica para mejorar la eficiencia de las misiones de vigilancia remota realizadas por los servicios de seguridad nacional a lo largo de la zona costanera. Considerando la no linealidad de la dinámica de un UAV, así como la inexistencia de información sobre el entorno, se ha diseñado una estructura jerárquica de control compuesta por una estrategia adaptativa de PID basada en un controlador MPC. La implementación del controlador adaptativo PID basado en MPC conduce a mejorar significativamente la tarea de seguimiento de trayectoria óptima del UAV, así como a satisfacer propiedades tales como la adaptabilidad, el autoaprendizaje y la capacidad de manejar incertidumbres causadas por el comportamiento impredecible de las corrientes marinas y las cargas de viento, manteniendo características robustas de rendimiento. En este trabajo, la investigación de los efectos de las perturbaciones externas sobre la estabilización y precisión de posicionamiento del UAV considera flujos arremolinados y ráfagas de corta duración. Estos corresponden a procesos deterministas y aleatorios, son representados matemáticamente como funciones trigonométricas con amplitudes aleatorias determinadas por los coeficientes de perturbaciones y los períodos de carga de viento de las pulsaciones. El rango establecido se da mediante un conjunto de varias observaciones de cargas de viento en los territorios costeros de Ecuador. Los datos analizados son recogidos de la base de datos de las estaciones meteorológicas nacionales. Finalmente, el proceso de simulación del movimiento controlado perturbado del UAV a lo largo de una trayectoria lineal segmentada, así como el análisis de datos y gráficos, se llevan a cabo en el entorno de MATLAB.

ABSTRACT The Center of Molecular Immunology is an exponent of Cuban biotechnology institution dedicated to basic research, development, production and commercialization of biopharmaceuticals, with the aim of diagnosing and treating cancer and diseases related to the immune system. In this work, a bibliographic synthesis of research that was carried out in this center in the period from 2012 to 2018, was performed, with the purpose of analyzing the application of some Data Mining techniques in the evaluation of fermentation and purification stages of the process for obtaining biopharmaceuticals in three production facilities. The phases of Data Mining were characterized and the practical implication of the results was presented. Principal Components Analysis was applied as a descriptive model using THE UNSCRAMBLER software, and Artificial Neural Networks were applied as a predictive model using the MATLAB neural networks toolbox. The use of these models made it possible to extract useful information for decision making, thereby explaining the behavior of the parameters that influence the quality of the final product, as well as estimating important variables such as the concentration of the protein of interest in the fermentation supernatant and the performance of the purification stage, depending on the process variables that have the greatest influence on its behavior.

RESUMEN El Centro de Inmunología Molecular es una institución exponente de la biotecnología cubana dedicado a la investigación básica, desarrollo, producción y comercialización de biofármacos, con el objetivo de diagnosticar y tratar el cáncer, así como enfermedades relacionadas con el sistema inmune. En este trabajo se realizó una síntesis bibliográfica de investigaciones que se llevaron a cabo en este centro, en el periodo comprendido del 2012 al 2018, con el propósito de analizar la aplicación de algunas técnicas de Minería de Datos en la evaluación de las etapas de fermentación y purificación del proceso de obtención de biofármacos en tres instalaciones productivas. Se caracterizaron las fases de la Minería de Datos y se presentó la implicación práctica de los resultados. Se aplicó como modelo descriptivo el Análisis de Componentes Principales mediante el software THE UNSCRAMBLER, y como modelo predictivo las Redes Neuronales Artificiales con el empleo de la caja de herramientas de redes neuronales del MATLAB. La utilización de estos modelos permitió extraer información útil para la toma de decisiones, se logró con ello explicar el comportamiento de los parámetros que influyen en la calidad del producto final, así como estimar variables de importancia como la concentración de la proteína de interés en el sobrenadante de la fermentación y el rendimiento de la etapa de purificación, en función de las variables del proceso que mayor influencia tienen en su comportamiento.

ABSTRACT The growing development in the automation of technological processes requires process engineers to know basic aspects of automatic regulation systems. In Plan E of Chemical Engineering, the subject Instrumentation and Controls is taught so that the graduate can conceive a regulation and control scheme for a technological process. The objective of the work is: Design a support software for Topic 3 of the Instrumentation and Controls subject, for the tuning of controllers using different criteria and the analysis of continuous time automatic regulation systems of technological processes. The AnaReg_V1 software was designed, which in the main window presents the regulation system block diagram that serves as an interface for the exchange of information, allowing to obtain the parameters of the first-order approximate model, tuning of either controllers or regulators of different types via different adjustment criteria and graph the temporal behavior of the regulation system variables. It is presented how employing AnaReg_V1 is obtained the approximated model, the tuning of an integral proportional controller according to the Ziegler-Nichols criterion and the temporary behavior of the variables of the regulation system taking as a study case the heat exchanger temperature control.

RESUMEN El creciente desarrollo en la automatización de procesos tecnológicos impone que los ingenieros de procesos conozcan aspectos básicos de los sistemas de regulación automática. En el plan E de Ingeniería Química se imparte la asignatura Instrumentación y Controles para que el egresado conciba un esquema de regulación y control para un proceso tecnológico. El objetivo del trabajo es: Diseñar un software de apoyo al Tema 3 de la asignatura Instrumentación y Controles, para el ajuste de controladores bajo diferentes criterios y el análisis de los sistemas de regulación automática de tiempo continuo de procesos tecnológicos. Se diseñó el software AnaReg_V1, el cual en la ventana principal presenta el diagrama de bloques de un sistema de regulación que sirve de interfaz para el intercambio de información, permitiendo obtener los parámetros del modelo aproximado de primer orden, ajustar controladores o reguladores de diferentes tipos bajo diferentes criterios de ajuste y graficar el comportamiento temporal de las variables del sistema de regulación. Se presenta como con AnaReg_V1 se obtiene el modelo aproximado, el ajuste de un controlador proporcional integral según el criterio Ziegler-Nichols y el comportamiento temporal de las variables del sistema de regulación tomando como caso de estudio el control de la temperatura de un intercambiador de calor.

ABSTRACT In this paper, the results carried out about a study over the possibilities of the Predictive Functional Control (PFC) are presented. The French professor Jacques Richalet and his collaborators developed the PFC. The results presented were obtained, when PFC is applied to industrial processes with complex dynamics such as high order, integral effects in the direct step that make the process asymptotically unstable in open loop and the undesirable phenomena of delay and inverse response. The main objective of the study is to demonstrate the potential offered by the PFC algorithm, in its simplest form, for the control of such processes. To this end, a methodology for synthesizing the PFC controller is developed based on the postulates and principles proposed by the precursors of the method, applied to several real case studies. In all cases, completely satisfactory results were obtained by means of simulation in Simulink-MatLab and finally the results of applying the method to the temperature control of the TCLab minilaboratory developed at the University of Utah are compared. This verifies the real possibilities of the FPC as a prominent alternative to control of real process.

RESUMEN En el presente artículo se exponen los resultados de un estudio realizado sobre las posibilidades que brinda el Control Predictivo Funcional (PFC en inglés) creado por el profesor francés Jacques Richalet y sus colaboradores, cuando el mismo es aplicado a procesos industriales con dinámicas complejas como son: el alto orden, efectos integrales en el paso directo que hacen que el proceso resulte asintóticamente inestable a lazo abierto y los fenómenos indeseables del retardo y la respuesta inversa. Como propósito del trabajo se pretende demostrar la potencialidad que brinda el algoritmo PFC, en su forma más simple, para el control de tales procesos. Para ello se elabora una metodología de síntesis del controlador PFC a partir de los postulados y principios planteados por los precursores del método, aplicada a varios casos de estudio reales. Se obtiene, en todos los casos, resultados totalmente satisfactorios, los cual se demuestra mediante simulación en Simulink-MatLab y finalmente se comparan los resultados de aplicar el método al control de temperatura del minilabortario TCLab elaborado en la Universidad de Utah. Queda así verificada la potencialidad del PFC como alternativa prominente para control real de procesos.

Resumen En este artículo se describe el procedimiento que permite diseñar un controlador para un convertidor Sepic de 2 kilovatios con elementos no ideales que puede ser usado en aplicaciones industriales. Se obtiene el modelo conmutado del convertidor a partir de los modos de operación, con este se construye el modelo en pequeña señal que permite obtener la función de transferencia necesaria para el diseño del controlador análogo, garantizado un tiempo de establecimiento de 25 ms. Se muestran los resultados de simulación usando MATLAB®/SIMULINK® alrededor del punto de operación realizando perturbaciones a la salida del convertidor y variaciones en el voltaje DC de entrada, evaluando el desempeño del sistema en el dominio temporal. Con el controlador diseñado se satisface la especificación de diseño para las resistencias internas de los inductores hasta 0.3 Ohmnios.

Abstract This paper describes a procedure for designing a 2-kilowatt SEPIC converter controller without ideal devices, to be used in industrial applications. A small-signal model can be constructed from a commuted converter in different operation modes. Subsequently, a transfer function is determined to design the analog controller, ensuring a settling time of 25 ms. The results around the operation point are shown using MATLAB®/SIMULINK®, and perturbations are applied to the converter output and the DC input voltage to evaluate performance in the time domain. The designed controller effectively meets the design specifications for disturbances near the operating point.

Abstract The energy transition involves changes in the dynamics of the provision of electric energy services and the insertion of new technologies. Within these technologies are DC microgrids, which, compared to traditional networks, have higher energy efficiency, lower installation and maintenance costs, and allow the simple integration of renewable sources. This paper presents dynamic small signal stability analysis for a DC microgrid, using the Runge Kutta integration method and the Matlab/Simulink tool. This DC microgrid is planned to be built in a Higher Education Institution in Colombia, and integrates different energy sources, such as solar, wind, storage systems, and also electric vehicles. The dynamic response of the DC microgrid is examined considering different operating conditions of generation and charging, and also different penetration scenarios of electric vehicles. The results show that to ensure the stability of the system in the face of variations in demand, it is essential to keep the electrical network in permanent operation, since it provides the necessary power that the microgrid cannot supply during times of greatest demand. Additionally, the power grid plays a vital role in regulating the voltage on the DC bus when loads increase. Therefore, to ensure the stability of the microgrid in various operating scenarios and demand levels, a connection with the electrical grid is essential.

Resumen La transición energética conlleva cambios en las dinámicas de prestación del servicio de energía eléctrica y la inserción de nuevas tecnologías. Dentro de estas tecnologías se encuentran las microrredes DC, las cuales, comparadas con las redes tradicionales, presentan mayor eficiencia energética, menores costos de instalación y mantenimiento, y permiten la integración simple de fuentes renovables. Esta investigación tuvo como objetivo el análisis dinámico de estabilidad de pequeña señal para una microrred DC. La metodología empleada utilizó el método de integración Runge Kutta y la herramienta Matlab/Simulink. Esta microrred DC se planea construir en una Institución de Educación Superior de Colombia, e integra diferentes fuentes de energía, como solar, eólica, sistemas de almacenamiento y también vehículos eléctricos. Se examinó la respuesta dinámica de la microrred DC considerando diferentes condiciones operativas de generación y carga, y también distintos escenarios de penetración de los vehículos eléctricos. Los resultados mostraron que, para asegurar la estabilidad del sistema ante variaciones en la demanda, es imprescindible mantener la red eléctrica en funcionamiento permanente, ya que esta aporta la potencia necesaria que la microrred no puede suministrar durante los momentos de mayor demanda. Además, la red eléctrica desempeña un rol vital en la regulación del voltaje en la barra DC cuando las cargas aumentan. Por lo tanto, para garantizar la estabilidad de la microrred en diversos escenarios de operación y niveles de demanda, la conexión con la red eléctrica resulta esencial.

Abstract This article presents a formulation for the optimization problem that minimizes the CO2 emission of pile caps with variations of geometry and pile position. The problem is defined by the design variables: concrete pile cap dimensions, rebar ratio, concrete compressive strength, the number of piles, the diameter, and length. The environmental impact was chosen as the objective function, taking CO2 emission as the main parameter. The design procedure was based on the ABNT NBR 6118:2014 (2014), and by the formulation proposed by Blévot & Frémy (1967). Also, the soil structure interaction between the cap and the piles was considered in the optimization problem. The problem was implemented using MATLAB (2016) and solved via a Genetic Algorithm native to the program. Results obtained from numerical examples were compared with structural designs solutions located in the Grande Vitória metropolitan area, Espírito Santo, Brazil and validated with a commercial software. The analyses indicate that design optimizations of pile caps considering the compressive strength of concrete, the diameter and length of piles and the optimal geometry of the pile caps may lead to significant reductions of material consumption, and consequently, a reduction of environmental impacts. CO position variables dimensions ratio function parameter 61182014 6118 2014 6118:201 2014, , (2014) 1967. 1967 . (1967) Also 2016 (2016 program area Santo software consumption consequently impacts 6118201 611 201 6118:20 (2014 196 (1967 (201 611820 61 20 6118:2 19 (196 (20 61182 6 2 6118: 1 (19 (2 (1 (

ABSTRACT A tidal thermal power plant is a system capable of using of ocean thermal gradients to produce electricity. It is a thermal machine in which surface water acts as a heat source, while water extracted from the depths acts as a coolant. The aim is to mathematically model the open cycle or Anderson tidal thermal power plants located on the coast and connected to the electrical system. For that, the bibliography related to the elements that make up this plant was reviewed, each component was mathematically modeled, from the functional diagram proposed by the authors, the model of these plants was obtained in MatLab/Simulink, which allowed to determine for a given scenario the power produced by the generator and the delivery of electrical energy to the electrical system.

RESUMEN Una central maremotérmica es un sistema capaz de aprovechar los gradientes térmicos oceánicos para producir electricidad. Se trata de una máquina térmica en la que el agua superficial actúa como fuente de calor, mientras que el agua extraída de las profundidades actúa como refrigerante. El objetivo es modelar matemáticamente las centrales maremotérmicas de ciclo abierto o de Anderson emplazadas en la costa y conectadas al sistema eléctrico. Para esto se revisó la bibliografía relacionada con los componentes de esta central, se modeló matemáticamente cada componente, a partir del diagrama funcional propuesto por los autores de este trabajo, se obtuvo el modelo de dichas centrales en MatLab/Simulink, lo que permitió determinar para un escenario dado la potencia producida por el generador y la entrega de energía eléctrica al sistema eléctrico.

Abstract A topological index is a branch of chemical graph theory that is vital to analyzing the physio-chemical characteristics of chemical compound structures divided into a degree-based molecular structure such as Zagreb indices, a distance-based molecular structure such as Wiener index, and a mixed such as Gutman index. In this paper, some definitions, results, and examples of Wiener polynomial and index for subdivision graph of friendship, and bifriendship graphs, line subdivision graph of friendship, and bifriendship graphs were introduced. Moreover, we used the MATLAB program to calculate the Wiener polynomial and index of these graphs and refer to some applications.

Abstract This paper introduces the Julia programming language as a dynamic, cost-effective, and efficient framework for implementing structural analysis packages. To achieve this, the finite element method was implemented for plane frames addressing the elastic instability problem through the Finite Element Method (FEM). Julia is a language open source, multiplatform, high-level and high-performance for technical and scientific computing, its compiler allows you to achieve speeds comparable to languages such as C and FORTRAN, but with more productive development dynamics due to its programming flexibility. Benchmarks between Julia and MATLAB are employed to discuss the processing costs, the programming techniques and paradigms used for computational performance. The results demonstrate that Julia performed the same analysis as the language used for comparison in 88.40% of the time, in addition to the fact that in loops comparisons case it reached 41.7% of the time for iteration, confirming its significant potential as a development tool of computational packages for structural analysis and scientific computing in general. dynamic costeffective, costeffective cost effective, effective cost-effective this FEM. FEM . (FEM) source multiplatform highlevel high level highperformance performance FORTRAN flexibility costs 8840 88 40 88.40 417 41 7 41.7 iteration general (FEM 884 8 4 88.4 41. 88.

Abstract Recently, the renewable energy applications require the development of highly efficient DC-DC converters with higher voltage transfer gain capability to meet out the increased global power demand. The non-isolated DC-DC converters are preferred due to certain drawbacks of isolated structures. The traditional boost, SEPIC (single-ended primary-inductor converter), and CUK based DC-DC converter structures are modified with additional power switches, diodes, and passive components in order to achieve high voltage gain. However, the modified structures with large number of active and passive elements suffer from the drawbacks of increased complexity of control algorithm, reduced power conversion efficiency and higher converter cost. Hence, the researchers started to explore more on single power switch configured non-isolated high step-up DC-DC converter topologies using hybrid concept. The research work presented in this paper explores such a high gain single-switch hybrid DC-DC converter structure that combines the conventional SEPIC and CUK topologies to achieve enhanced voltage gain. In the proposed hybrid topology, the input current is continuous during all modes of converter operation. Moreover, the power switch experiences only low voltage-current stress. The closed-loop configuration of the proposed hybrid converter is implemented using classic PID (Proportional+Integral+Derivative) and FOPID (Fractional Order PID) controllers, and simulated in MATLAB / SIMULINK environment with duty ratio D = 0.7 for the power switch. The results demonstrate that the dynamic performance of the converter with FOPID controller is much improved in terms of reduced settling time, overshoot, and ripples for the output voltage, as compared to that with classic PID controller. Recently DCDC DC demand nonisolated non boost singleended ended primaryinductor primary inductor converter, , converter) switches diodes However algorithm cost Hence stepup step up concept singleswitch topology operation Moreover voltagecurrent stress closedloop closed loop Proportional+Integral+Derivative ProportionalIntegralDerivative Proportional Integral Derivative (Proportional+Integral+Derivative Fractional controllers 07 0 7 0. time overshoot