Vicente Fuster-Roig

During the last decade, many works have proven the important benefits of the analysis of different quantities under transient regimes for enhancing the diagnostic of the condition of electric motors. For instance, the analysis of starting currents and stray fluxes has proven to be very effective to avoid false indications obtained with classical tools, as well as to discriminate among different types of failures. The optimization of signal processing tools and image recognition algorithms that were too computationally expensive years ago has facilitated the proliferation of transient analysis techniques in the condition monitoring area. Moreover, the use of modern artificial intelligence (AI) methods has enabled us to start implementing them in autonomous condition monitoring systems. Despite initially applied to induction motors and specific transient regimes and quantities, the use of these methodologies is being expanded to other machine typologies, other transients and even other quantities. This work compiles the recent advances in this area and proposes the extrapolation of startup transient analysis to other quantities such as vibrations. It is shown that the simultaneous analysis of different quantities under transient regimes enables us to enhance the diagnostic and even to cover a wider range of faults.

The transition to decarbonized and distributed energy systems has increased interest in flexibility markets as a key tool to manage variability and coordinate distributed energy resources. However, the fast growth and conceptual fragmentation of this field hinder the building of coherent models and scalable solutions. This paper presents a scoping review of 243 peer-reviewed articles published between 2013 and 2025, applying the TEAM Framework and Business Model Canvas. Through a structured data matrix of 35 variables, we analyze how flexibility is defined and modelled, the coordination mechanisms applied, and how business dimensions are integrated. The results reveal major inconsistencies in terminology, actor roles, price formation, and interoperability modelling. We identify critical gaps in cost modelling and business model integration, especially in low-TRL studies. This review provides a comprehensive and cross-cutting synthesis of existing approaches, offering a reference framework for future research, policy design, and market implementation of distributed flexibility mechanisms.

Underground electrical conductors, both medium-and high-voltage, play a crucial role in energy infrastructure. However, they present a maintenance challenge due to their difficult access. Unlike overhead installations, these cables remain hidden, making it harder to obtain key parameters, such as their temperature or structural condition, in a simple manner. Current temperature measurement methods, including fiber-optic-based systems (DTS and LTS), involve high costs that limit their feasibility in medium-voltage networks, where more economically accessible alternatives are required. This study introduces an alternative system for monitoring the temperature of underground cables using NTC thermistors. Its design allows for reducing the number of connection conductors for sensors to just four regardless of the number of measurement points. The implemented measurement technique is based on the sequential activation of sensors and the integration of the recorded current to achieve an accurate thermal assessment. The tests conducted validate that this proposal represents an efficient, cost-effective, and highly scalable solution for implementation in electrical distribution networks.

Sweep Frequency Response Analysis (SFRA) applied to rotating machine diagnosis and monitoring lacks of widespread industrial applicability up to this date. Several authors identify the rotor position influence as one of the main obstacles for an on-site and reliable diagnosis. This work provides a thorough investigation on how the rotor affects the broadband impedance for different rotor topologies. The rotor DC field is identified as a strong influence on the measured broadband impedance. First, a theoretical analysis is performed to study the effect of an external DC field in the broadband impedance. Then, a 4.7 kW PMSM is thoroughly analyzed including magnetostatic Finite Element Analysis (FEA) and experimental measurements. Finally, the influence of magnetic remanence on the broadband impedance is experimentally studied. To this aim, two induction machines with two different rotor types (i.e., wound-rotor and squirrel cage) are analyzed. This collection of results is aimed to clarify the physics behind the rotor position influence and to enhance the reliability of SFRA diagnosis for rotating machinery.

Wound rotor induction motors (WRIM) are commonly used in applications requiring high starting torques. This is due to the possibility of adding external rheostats in series with the rotor winding that enhance their speed-torque characteristics. However, they are more prone to failures due to their greater constructive complexity. Previous works demonstrated that the combined application of steady-state (Motor Current Signature Analysis) and transient stator current-based methodologies enables a robust diagnosis of rotor asymmetries. However, few works have considered thedetection of stator winding asymmetries (a type of failure that is rather frequent in field WRIM). On the other hand, even fewer works have explored the suitability of rotor current analysis for diagnostic purposes. This work proposes the advanced analysis of rotor currents for the detection of stator asymmetries in WRIM. The proposed novel methodology is based on the combined application of steady-state and transient-based methods to rotor current signals. Unlike what happens in Cage Induction Motors (CIM), rotor currents can be easily measured in WRIM in a simple, reliable and economic way; these are interesting advantages for a reliable WRIM condition monitoring compared to other solutions. The laboratory results prove that it is possible to discern the harmonics caused by different levels of stator asymmetries in the FFT spectrum of steady-state rotor currents. Also, the fault also yields characteristic patterns in the time-frequency maps resulting from the analyses of rotor currents under the starting. These results are validated with an industrial environment in two different large field motors operating in cement plants. This proves the powerfulness of the approach to diagnose the presence of the considered failure.

Industrial manufacturing processes have evolved and improved since the disruption of the Industry 4.0 paradigm, while energy has progressively become a strategic resource required to maintain industrial competitiveness while maximizing quality and minimizing environmental impacts. In this context of global changes leading to social and economic impact in the short term and an unprecedented climate crisis, Digital Twins for Energy Efficiency in manufacturing processes provide companies with a tool to address this complex situation. Nevertheless, already existing Digital Twins applied for energy efficiency in a manufacturing process lack a flexible structure that easily replicates the real behavior of consuming machines while integrating it in complex upper-level environments. This paper presents a combined multi-paradigm approach to industrial process modeling developed and applied during the GENERTWIN project. The tool allows users to predict energy consumption and costs and, at the same time, evaluates the behavior of the process under certain productive changes to maximize consumption optimization, production efficiency and process flexibility.

Las Tecnologías de la Información y la Comunicación (TIC) se han vuelto indispensables en el nuevo modelo educativo híbrido, donde se combina la enseñanza presencial con la enseñanza online. Profesores y estudiantes deben adaptarse y participar activamente en el proceso de aprendizaje para aprovechar el máximo estas tecnologías, las cuales permiten una mayor accesibilidad y flexibilidad en la educación, mejorando la personalización y la colaboración del aprendizaje . En concreto, en este trabajo expone diferentes experiencias en el uso de material multimedia interactivo para ayudar a los estudiantes de las asignaturas de “Teoría de Circuitos” y “Electromagnetic experiments and their theoretical foundations” de la Escuela Técnica Superior de Ingenieros Industriales de la Universitat Politècnica de València, los cuales tienen dificultades para comprender los conceptos básicos de las asignaturas, lo que se refleja en los malos resultados que obtienen en las evaluaciones. Con la implementación de estos nuevos recursos multimedia se pretende mejorar la motivación del alumno y facilitar el aprendizaje de cada concepto o método explicado en las asignaturas. Tras su implementación, se muestra que dichas actividades mejoran significativamente el rendimiento de los estudiantes, obteniendo resultados positivos tanto en utilidad como en facilidad de uso por parte de los estudiantes.

This paper proposes the qualitative and quantitative analysis of stray-flux and current data under starting to detect damper faults in cylindrical rotor synchronous machines. These machines are typically employed in high power applications and their possible outages may imply huge costs for the industries or plants where they operate. The damper cage is a critical part of these machines and a potential source of catastrophic failures. However, few research works have provided feasible alternatives to monitor the condition of such element. This work analyses the viability of analyzing the electromotive force signals induced by the stray-flux in external coil sensors as well as current signals under starting to diagnose damper faults. The results obtained with laboratory machines with different levels of damper damage show that the analyses of those signals can provide very useful information for determining how the damper degrades over time. Moreover, the paper studies the effect of the remanent magnetism over the viability of the approaches and provides solutions to overcome this problem. The conclusions are valuable for field engineers since, nowadays, there are few available solutions that allow monitoring the condition of such element without motor disassembly.

Moist polluting substances on high-voltage insulator surfaces can cause power-line failures by triggering electric arcs. There are at present no effective methods of measuring insulator pollution levels during normal operations. In this work, we attempt to estimate insulator pollution leakage current (PLC) as an indirect method of measuring deposits in a 30 month period of simultaneously recording leakage current and related environmental variables in substation insulators. We analyzed the relationship between raw leakage current and environmental variables. We canceled out the influence of relative humidity on leakage current by adaptive filtering and then obtained the PLC by filtering out the anomalous peaks in the recording. The proposed method considerably reduces the correlation between leakage current and relative humidity (0.826 vs 0.019). The resulting signal was only slightly correlated with other environmental variables (<0.03), suggesting that the relationships between leakage current and temperature, wind direction and speed are mainly attributable to their influence on relative humidity. The PLC presents a quasi-annual smooth fluctuation over time with a magnitude similar to those obtained in laboratory tests. This novel technique could be used to monitor insulator PLC in real time and thus improve power supply continuity and reduce maintenance costs.