María Alejandra Mantilla Villalobos

High Voltage Direct Current (HVDC) transmission has emerged as an efficient solution for transporting large amounts of electrical power over long distances, particularly in scenarios requiring high controllability and system stability. Among the available technologies, Voltage Source Converters (VSC) based on Modular Multilevel Converters (MMC) have become a prominent option due to their scalability, superior waveform quality, and operational flexibility. In this context, this work considers the use of a full-bridge MMC topology for a rectifier station in HVDC systems, selected for its enhanced robustness under DC-side conditions and its improved control capabilities compared to other configurations. The main contribution of this paper is the implementation of a deadbeat predictive current control strategy in the abc reference frame, directly applied to converter variables without requiring coordinate transformations. This approach enables an accurate current tracking. Additionally, a DC bus controller based on a PI regulator is incorporated to regulate the DC-side voltage and generate the current reference signals required by the predictive controller. The modulation stage is implemented using Phase-Shifted Carrier Pulse Width Modulation (PSC-PWM), which is particularly well suited for multilevel converters due to its inherent capability to balance submodule capacitor voltages, effectively distribute switching events, and mitigate voltage ripple in the DC bus. The development and analysis of such control strategies are particularly relevant in contexts such as Colombia, where HVDC implementation is still in early stages. In particular, initiatives such as the GCM (Guajira–Cesar–Magdalena) transmission expansion plan aim to integrate large-scale renewable generation from the northern region into the National Interconnected System (SIN), highlighting the need to strengthen technical capabilities in advanced power conversion and control technologies in emerging HVDC-based infrastructures. Accordingly, this work adopts this case study as a reference for the sizing of the simulated system. The system is modeled in MATLAB/Simulink, and its performance is evaluated under steady-state operating conditions through the analysis of electrical variables, including waveform quality and metrics such as Total Harmonic Distortion (THD) and Mean Square Error (MSE). The results enable the observation of the converter behavior under the implemented control scheme and demonstrate the superior performance of the MMC topology compared to a conventional two-level three-phase full-bridge converter. This work provides an integrated control framework for MMC-based HVDC rectifier stations, combining predictive current control, DC bus regulation, and PSC-PWM, all implemented directly in the abc reference frame without requiring additional coordinate transformations.

The rapid expansion of photovoltaic (PV) generation has increased the need for educational and experimental platforms that allow students and researchers to study the dynamics, control strategies, and power conversion stages of grid-connected PV systems under realistic operating conditions. Although Hardware-in-the-Loop (HIL) simulation is widely used to validate power electronic converters and control algorithms, many existing platforms rely on specialized real-time simulators that limit their accessibility in academic environments. This paper presents the design and implementation of a cost-effective HIL simulation platform for grid-connected PV systems intended for research and training applications. The proposed system integrates real hardware under test within a real-time environment that emulates PV array behavior and grid conditions, combining Controller Hardware-in-the-Loop (CHIL) and Power Hardware-in-the-Loop (PHIL) techniques. A Texas Instruments C2000 microcontroller is used as the real-time digital simulator, providing an accessible alternative to conventional real-time simulation platforms. The platform architecture, the real-time PV emulator, and the experimental implementation are described and validated through simulation and experimental results. Finally, guided laboratory practices are presented to support hands-on training in PV systems and power electronics.

Introduction: Bidirectional DC/DC converters are employed in energy management systems in applications such as electric vehicles with regenerative braking. The design of robust control strategies for these systems requires accurate dynamic models that are computationally efficient compared to full switching models. This paper presents the development of steady-state averaged (DC) models and small-signal dynamic (AC) models for the four operating modes of a cascaded bidirectional buck–boost converter topology operating in continuous conduction mode (CCM). Objective: To develop a unified bidirectional canonical model that represents the dynamics of the cascaded buck-boost converter in a standardized form for all four operating modes. Methods: Steady-state averaged models (DC) and small-signal dynamic models (AC) were developed for the four operating modes in continuous conduction mode using state-space averaging, perturbation, and linearization methods. The canonical model was implemented in MATLAB/Simulink. Results: A unified bidirectional canonical model was derived, facilitating analysis and design. The model was validated by comparing its dynamic response with a conventional switching model under step changes in the input voltage, demonstrating high fidelity. Conclusions: The proposed averaged model is validated as an accurate and computationally efficient tool for the design of control systems in these applications. Keywords: Cascaded buck-boost bidirectional converter, canonical model, state-space averaging method, small-signal AC model.

Los sistemas de conversión de la energía eléctrica empleados en las plantas solares fotovoltaicas han venido en constante avance en las últimas décadas, buscando mejorar la eficiencia y calidad del suministro de la energía, así como garantizar la confiabilidad y estabilidad del sistema de potencia. Entre los avances destacan las topologías de conversión multinivel las cuales presentan múltiples beneficios respecto a las topologías tradicionales, como la reducción de la distorsión armónica en las señales de tensión y corriente, y una mayor eficiencia energética en aplicaciones de media y alta potencia. Asimismo, el desarrollo de estrategias de control y gestión energética es un factor clave para el adelanto de estos sistemas de acondicionamiento de la energía. Estas estrategias permiten la inclusión de nuevas funcionalidades y capacidades operativas a las plantas fotovoltaicas, contribuyendo así a dar respuesta a los desafíos que enfrentan los sistemas modernos de potencia ante la creciente integración de recursos energéticos distribuidos y la implementación de tecnologías emergentes. En este contexto, este trabajo presenta el diseño y la implementación de un sistema de control de potencia para un inversor trifásico multinivel en topología de puentes H en cascada (CHB por las siglas en inglés de cascaded H-bridge). El sistema de control diseñado permite regular la potencia activa y reactiva entregada por el sistema fotovoltaico a la red, mediante una estrategia de generación de corriente de referencia implementada en los ejes coordenados abc, sin requerir de transformaciones entre marcos de referencia adicionales. La regulación de la corriente inyectada se realiza mediante controladores proporcionales resonantes y la técnica de modulación por ancho de pulso por desplazamiento de nivel adecuada para la topología multinivel considerada. El desempeño del sistema de control fue evaluado experimentalmente en un prototipo de inversor CHB de tres niveles del Grupo de Investigación en Sistemas de Energía Eléctrica (GISEL) de la Universidad Industrial de Santander (UIS). Los resultados experimentales confirmaron el correcto funcionamiento de los sistemas de control diseñados, lo que se evidenció en el seguimiento preciso de las corrientes de referencia y en los desfases entre las corrientes inyectadas y las tensiones en el punto de acoplamiento común, de acuerdo con el factor de potencia establecido en cada prueba. Este documento presenta los resultados del trabajo final de pregrado en Ingeniería Eléctrica de la UIS titulado “Sistema de control de potencia para un inversor fotovoltaico multinivel en topología de puentes H en cascada”.

Due to climate change, the temperature monitoring of reinforced-concrete (RC) structures is becoming critical for preventive maintenance and extending their lifespan. Significant temperature variations in RC elements can affect their natural frequencies and modulus of elasticity or generate abnormal stress levels, potentially leading to structural damage. Data from thermal monitoring systems are invaluable for testing and validating numerical methodologies for estimating internal thermal responses and aiding in prevention/maintenance decision making. Despite its importance, few experimental outdoor data on the internal and external temperatures of concrete structures are available. This study presents a comprehensive dataset from a 120-day temperature-monitoring campaign on a 1.2 m long reinforced-concrete slab-on-I-beam model under tropical conditions in Bucaramanga, Colombia. The monitoring system measured the internal temperatures at 40 points using embedded thermocouples, while the surface temperatures were recorded with handheld and drone-mounted thermal cameras. Simultaneously, the ambient temperature, solar radiation, rainfall, wind velocity, and other parameters were monitored using a weather station. The instrumentation ensured the synchronization and high spatial resolution of the thermal data. The data, collected at 30 min intervals, are openly available in CSV format, offering valuable resources for validating numerical models, studying thermal gradients, and enhancing structural health-monitoring frameworks.

In the energy transition context, electrical microgrids facilitate the integration of renewable generation into the electrical grid, improving the electrical system's reliability and accelerating its decarbonization. However, to promote the technological advancement of these grids, it is necessary to develop tools to validate new technologies and solutions, such as using the Internet of Things (IoT) for their operation and control. This work presents the design, implementation, and validation of an IoT system for an experimental laboratory microgrid developed at Universidad Industrial de Santander. The main design phases of the IoT system are described, beginning with the definition of requirements and extending through the component selection. Validation tests are proposed to verify the functionalities of the IoT system. The results demonstrate that the IoT system successfully enables the transmission and reception of data from external users and servers. The reported experience and the proposed validation tests are relevant for researchers interested in implementing IoT-based stages in existing or future laboratory microgrids.

Este trabajo presenta el diseño y la implementación de un módulo didáctico de laboratorio, basado en un convertidor electrónico de potencia para el desarrollo de prácticas experimentales de la asignatura electrónica de potencia en la Universidad Industrial de Santander (UIS). El módulo didáctico constituye una herramienta educativa de apoyo para los procesos de enseñanza y aprendizaje en la formación de estudiantes de las carreras de Ingeniería Eléctrica e Ingeniería Electrónica. La topología del convertidor electrónico implementado corresponde a un rectificador trifásico en puente completo no controlado seguido de un inversor trifásico en puente completo controlado; resultando en un proceso de conversión de la energía en dos etapas que puede ser empleado para la realización de prácticas experimentales en diversas aplicaciones. Se diseñaron e implementaron los circuitos de potencia, adecuación y aislamiento de señales, y control del prototipo, los cuales fueron verificados mediante simulaciones en Matlab/Simulink y pruebas experimentales en laboratorio, para garantizar el correcto funcionamiento en el ensamble final. Para la implementación de la etapa de control del módulo de laboratorio, se empleó la plataforma Arduino Mega, la cual es de fácil programación para estudiantes de pregrado. De esta manera, los estudiantes pueden proponer e implementar la estrategia de control del convertidor de potencia dependiendo de la práctica que se desee realizar, permitiendo al profesor abordar estrategias de aprendizaje basadas en problemas o retos. Además, se elaboró un manual de usuario y guías de laboratorio que permiten brindar información sobre el principio de operación del convertidor y el funcionamiento del módulo, y orientan la realización de prácticas experimentales en la asignatura electrónica de potencia. Esta herramienta educativa ofrece numerosos beneficios como la apropiación y verificación de conocimientos, la realización de pruebas experimentales con sistemas de conversión de la energía, el desarrollo de competencias teórico-prácticas, y el análisis y la interpretación de datos resultantes de la experimentación. Este documento presenta los resultados del trabajo final de pregrado en Ingeniería Eléctrica de la UIS titulado “Módulo didáctico de inversor de potencia para prácticas experimentales de laboratorio” realizado en el marco del proyecto de investigación interno titulado "Estrategia pedagógica para el fortalecimiento de competencias en STEM mediante sistemas modulares de laboratorio", código 2825.

Multi-functional photovoltaic (PV) inverters incorporate ancillary services to enhance power quality and mitigate stability issues in distribution networks. These next-generation PV inverters will achieve a higher utilization of the inverter’s rated capacity, improving the cost-effectiveness of PV technology. However, the power required to perform ancillary services, such as load compensation capabilities, could exceed the inverter’s capacity, risking the components’ integrity. Therefore, multi-functional control algorithms must limit the power capacity according to the system’s nominal currents. Despite this, most control proposals do not address this issue when load balancing capabilities are included for PV inverter control. This paper proposes a flexible control strategy for three-phase multi-functional PV inverters, considering load balancing functionalities while keeping the inverter currents within safe operating limits. The proposal introduces two control parameters whose variation results in different load compensation capabilities. These parameters can be adapted dynamically according to the inverter rated capacity not used for active power injection and the load compensation requirements. Additionally, a control algorithm is proposed to limit the inverter current according to the nominal values supported by the device. This algorithm also allows setting compensation objectives following a priority scheme in which the injection of the PV active power is prioritized over the load compensation functionalities. Reactive power compensation and load balancing functionalities are also considered at a lower level of hierarchical priority. The proposal was evaluated through experimental tests on a multi-functional PV inverter prototype under various operational conditions. The experimental results show an excellent control strategy performance, achieving the control objectives under unbalanced load conditions.

The study of thin-film solar cells based on tin sulphide is becoming increasingly relevant due to its advantages over similar technologies, such as its low cost, toxicity, and the fact that its constituent elements are more abundant in the earth's crust; besides, they could be made by thigh vacuum techniques like thermal spraying, sputtering, co-evaporation, or thermal evaporation. On the other hand, Simulations allow modelling of the behaviour of solar cells to understand the processes and improve the device's efficiency. Therefore, in this work, the simulation process is carried out using mathematical models that represent the physical behaviour of the solar cell made of heterojunction of several thin films with ZnO/ZnS/SnS configuration. Two radiation models were evaluated, one using a theoretical equation and the other with data from the incident radiation. Until today, different simulations of solar cells have been carried out mainly using a Solar Cell Capacitance Simulator (SCAPS); however, this research was developed using MATLAB due to its performance and efficiency. The optimal thickness of the absorbent layer was established from the results obtained for open circuit voltage (Voc), short circuit current density (Jsc), fill factor and conversion efficiency (n).