Person: Elizondo Martínez, David
Loading...
Email Address
person.page.identifierURI
Birth Date
Research Projects
Organizational Units
Job Title
Last Name
Elizondo Martínez
First Name
David
person.page.departamento
Ingeniería Eléctrica, Electrónica y de Comunicación
person.page.instituteName
ISC. Institute of Smart Cities
ORCID
0000-0002-6993-0631
person.page.upna
811410
Name
12 results
Search Results
Now showing 1 - 10 of 12
Publication Open Access Asymmetrical firing angle modulation for 12-pulse thyristor rectifiers supplying high-power electrolyzers(IEEE, 2023) Iribarren Zabalegui, Álvaro; Barrios Rípodas, Ernesto; Elizondo Martínez, David; Sanchis Gúrpide, Pablo; Ursúa Rubio, Alfredo; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio IngeniaritzarenThis paper presents an asymmetrical firing angle modulation strategy for 12-pulse thyristor rectifiers aimed at supplying high-power electrolyzers, which allows to reduce the size of the passive filter and the static compensator (STATCOM) required to comply with grid harmonic regulations and achieve unity power factor. Usually, 12-pulse thyristor rectifiers follow a symmetric modulation strategy in which the same firing angle is applied to both 6-pulse bridges. In this case, large passive ac-side inductances are required to reduce grid current harmonics, which increase the reactive power consumption and thus the required STATCOM size. However, this paper demonstrates that by applying different firing angles to the two 6-pulse bridges it is possible to comply with the harmonic regulation limits using smaller filtering inductances and therefore reducing the STATCOM size. The methodology to find the optimal firing angle values that should be applied in order to minimize the filtering inductance and the STATCOM size for a given electrolyzer is explained. This strategy is validated by simulation, and results show that the required filtering inductance and the apparent power of the STATCOM can be effectively reduced by 62% and 31%, respectively, using this asymmetrical firing angle modulation.Publication Open Access Dynamic modeling of a pressurized alkaline water electrolyzer: a multiphysics approach(IEEE, 2023) Iribarren Zabalegui, Álvaro; Elizondo Martínez, David; Barrios Rípodas, Ernesto; Ibaiondo, Harkaitz; Sánchez Ruiz, Alain; Arza, Joseba; Sanchis Gúrpide, Pablo; Ursúa Rubio, Alfredo; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio IngeniaritzarenIn this paper a dynamic model for the simulation of pressurized alkaline water electrolyzers is presented. The model has been developed following a multiphysics approach, integrating electrochemical, thermodynamic, heat transfer and gas evolution processes in order to faithfully reproduce the complete dynamical behavior of these systems. The model has been implemented on MATLAB/Simulink and validated through experimental data from a 1 Nm3/h commercial alkaline water electrolyzer. Validations have been performed under real scenarios where the electrolyzer is working with power profiles characteristic from renewable sources, wind and photovoltaic. The simulated results have been found to be consistent with the real measured values. This model has a great potential to predict the behavior of alkaline water electrolyzers coupled with renewable energy sources, making it a very useful tool for designing efficient green hydrogen production systems.Publication Open Access Role of student associations in the acquisition of competences in university engineering programs(IEEE, 2023) Samanes Pascual, Javier; Parra Laita, Íñigo de la; Berrueta Irigoyen, Alberto; Rosado Galparsoro, Leyre; Soto Cabria, Adrián; Elizondo Martínez, David; Catalán Ros, Leyre; Sanchis Gúrpide, Pablo; Institute of Smart Cities - ISCStudents in the STEM field (Science, Technology, Engineering and Mathematics), do not only require deep technical knowledge, but a complete set of global skills related to management, teamwork, lifelong learning, personal development, communications skills or proactiveness, abilities often referred as soft-skills. Student-led organizations, and specifically, university student associations, are one of the best alternatives to promote the acquisition of soft-skills in STEM high education fields. These skills are competences already included in official university programs that can hardly be addressed or acquired from traditional university education. This article studies how student enrollment in student led organizations (SLOs), with an active participation on their organization and activities, allows engineering students to achieve a better development of these soft skills. As case study, a medium size university, with 9000-students and eleven SLOs, six of them focused on STEM related fields, is used in this paper. A survey is conducted among the university community to identify their degree of participation in SLOs, and to test whether participation in these initiatives increases students' self-perception of their soft skill acquisition during their university studies. This survey shows how students of engineering programs, with a high degree of involvement in SLOs, demonstrated greater confidence in their soft skills at the end of their university years.Publication Open Access Diseño y comparativa de dos técnicas de control de un inversor fotovoltaico para conexión a una red monofásica(2017) Elizondo Martínez, David; Urtasun Erburu, Andoni; Escuela Técnica Superior de Ingenieros Industriales y de Telecomunicación; Telekomunikazio eta Industria Ingeniarien Goi Mailako Eskola TeknikoaEl presente Trabajo Fin de Grado estudia y diseña dos técnicas de control para un inversor fotovoltaico monofásico de pequeña potencia (6 kW) conectado a red. Dicho inversor fotovoltaico consta en ambos casos de un elevador y de un puente en H monofásico. El convertidor es diseñado (topología y elementos pasivos) en función de las particularidades de cada técnica de control. El primer control estudiado y diseñado se denomina técnica de control convencional, puesto que se trata de una técnica madura ampliamente estudiada y tratada, así como empleada en convertidores comerciales. El control se caracteriza esencialmente porque elevador y puente en H conmutan continuamente a alta frecuencia. El segundo control es definido como técnica de control alternativa. Introduce como innovación respecto del convencional que existen dos modos de funcionamiento diferenciados - Boost y Buck -, de manera que en cada uno de ellos solo conmuta a alta frecuencia una de las etapas. Por tanto, elevador y puente en H funcionan secuencialmente. El objetivo final es determinar cuál de las dos técnicas de control resulta más adecuada para aplicaciones fotovoltaicas conectadas a red y de baja potencia. El análisis de ambas y la comparación entre ellas concluyen que la técnica de control alternativa propuesta es superior al control convencional en que logra mayor eficiencia, requiere menor inductancia en el elevador y capacidad total similar, presenta menor distorsión armónica en la corriente de red y admite un rango más amplio de tensión de entradaPublication Open Access Winding resistance measurement in power inductors - understanding the impact of the winding mutual resistance(IEEE, 2021) Barrios Rípodas, Ernesto; Elizondo Martínez, David; Ursúa Rubio, Alfredo; Sanchis Gúrpide, Pablo; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio IngeniaritzarenInductors are cornerstone components in power electronics converters. Since winding loss is the dominant loss mechanism in these components, its accurate measurement is fundamental for the validation of the inductor's operation and design. The techniques for the winding resistance R_{w} measurement in power inductors can be classified into two groups, indirect and direct. Both techniques use coupled inductors to separate winding and core power losses. If coupled inductors with non-zero winding mutual resistances R_{w,m} are used, invalid results are obtained with these techniques. Understanding the meaning of R_{w,m} in coupled inductors is complex. In this paper, the impact of R_{w,m} on the inductor R_{w} measurement techniques is demonstrated and practical guidelines for the design of the zero R_{w,m} coupled inductors are given. Particularly, the location of the auxiliary winding for the direct technique is investigated. In order to compare the R_{w} measurement techniques and to validate the coupled inductor's R_{w,m} impact, two different inductors are built and tested. The results are compared with the values for R_{w} calculated by FEA simulation. It is found that only the direct technique with an auxiliary winding carefully designed and located following the guidelines given in this paper makes the accurate measurement of R_{w} in power inductors possible.Publication Open Access Zero-loss switching in LLC resonant converters under discontinuous conduction mode: analysis and design methodology(IEEE, 2023) Elizondo Martínez, David; Barrios Rípodas, Ernesto; Larequi, Íñigo; Ursúa Rubio, Alfredo; Sanchis Gúrpide, Pablo; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Universidad Pública de Navarra / Nafarroako Publikoa UnibertsitateMany thriving applications where isolation is required, such as LED drivers, traction and EV fast charging, implement LLC resonant converters, particularly when voltage regulation is not required or an additional conversion stage is in charge of it. The LLC converter can be operated under discontinuous conduction mode (DCM), due to its advantages such as unregulated and sensorless operation, fixed switching frequency and voltage gain, and zero-current switching (ZCS). However, ZCS results in EMI and switching losses in the primary converter, particularly for≥1200-V devices. Alternatively, zero-loss switching (ZLS) can be accomplished by means of a proper design of the LLC converter, overcoming the drawbacks of ZCS. The focus of this paper is to perform an exhaustive research on the LLC converter under DCM-ZLS: discontinuous conduction mode with lossless switching in the primary and secondary sides. As a result of this analysis, a set of design boundaries are deduced for parameters such as the magnetizing inductance, the leakage inductance, and the gate resistance. A comprehensive, step-by-step design methodology is proposed and applied to a 18-kW, 200-kHz test bench. The designed parameters are implemented in the converter and several experiments are conducted, including a test at rated input voltage and rated power (600 V, 18 kW). The conduction states studied theoretically in the analysis of the LLC converter are identified in the experimental results, and the operation of the test bench under DCM-ZLS is verified.Publication Open Access Analytical modeling of high-frequency winding loss in round-wire toroidal inductors(IEEE, 2023) Elizondo Martínez, David; Barrios Rípodas, Ernesto; Ursúa Rubio, Alfredo; Sanchis Gúrpide, Pablo; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Universidad Pública de Navarra / Nafarroako Unibertsitate PublikoaToroidal inductors are used in many industrial applications in which they are key components regarding cost and volume. In the inductor design process, it is paramount to accurately estimate its high-frequency winding loss. Finite-element analysis (FEA) software and analytical models can be used for this purpose. However, the former employs too much time and the latter lacks accuracy when applied to toroidal windings, leading to an overestimation that can exceed 200%. As a consequence, designers would benefit from a reliable method to calculate high-frequency loss in toroidal windings. This article proposes an analytical model that considers the 2-D characteristic of the magnetic field and the geometrical particularities of toroidal windings. Furthermore, it provides an easy-to-use method, which avoids the unaffordable computational cost of FEA software. Simulations and experimental measurements are carried out for seven toroidal power inductors, from 10 Hz up to 200 kHz. Three different well-known state-of-the-art analytical models are used for comparison purposes. The results obtained with the proposed model are in good agreement with those from FEA and the experiments. The proposed model shows a maximum deviation below 20% while the overestimation of the existing analytical methods reaches values from 93% to 226%.Publication Open Access Zero-loss switching in DC-DC series resonant converters under discontinuous conduction mode(IEEE, 2021) Elizondo Martínez, David; Barrios Rípodas, Ernesto; Sanchis Gúrpide, Pablo; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación; Universidad Pública de Navarra / Nafarroako Unibertsitate PublikoaMany thriving applications where isolation is required, such as traction and EV fast charging, implement solid-state transformers (SST). Half-cycle discontinuous-conduction-mode series resonant converters (HC-DCM-SRC) are suitable for these applications. The focus of this paper is to perform a comprehensive approach to HC-DCM-SRC and provide straight-forward requirements in order to ensure zero-loss switching (ZLS) of semiconductors. In addition, these requirements can be expressed as design boundaries for the transformer. Finally, the paper shows that, due to ZLS, silicon devices may have larger power capability than silicon-carbide switches. Therefore, IGBTs can be used instead of SiC MOSFETs, resulting in a significant cost reduction of the converter.Publication Open Access Dual-mode soft-transition control for single-phase grid-connected photovoltaic inverters(IEEE, 2018) Elizondo Martínez, David; Urtasun Erburu, Andoni; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de ComunicaciónSingle-phase grid-connected inverters for photovoltaic power generation have been strongly analysed for improvement. Dual-mode control for two-stage inverters makes it possible to improve the efficiency by alternating between switching the dc/dc boost and the dc/ac buck stages, depending on the grid voltage value. However, according to the literature, the transition from one mode to the other is abrupt, which harms the grid current quality. This paper proposes a dual-mode control method which achieves high efficiency and a soft-transition in the grid current. Applying suitable feed-forward compensations, this control method improves the grid current quality, as demonstrated by the presented simulation results.Publication Open Access Novel two-stage three-level converter with inherently-balanced dc voltage for EV fast-charging applications(IEEE, 2023) Elizondo Martínez, David; Barrios Rípodas, Ernesto; Galdeano Bujanda, Mikel; Ursúa Rubio, Alfredo; Sanchis Gúrpide, Pablo; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC; Universidad Pública de Navarra / Nafarroako Unibertsitate PublikoaThe design of EV fast chargers faces a new challenge due to the boost in the battery voltage of electric cars and heavyduty electric vehicles. Two-stage converters, that consist of an isolated dc-dc stage and an extra regulated dc-dc converter, are attracting an increasing attention thanks to their outstanding performance. The potential benefits of multilevel converters, such as lower power losses and more compact filters, can be incorporated to two-stage architectures at the expense of simplicity due to the need of a voltage balancing method. In this article, a novel dc-dc two-stage three-level (2S3L) architecture is presented, which guarantees that the multilevel input dc voltages are balanced without any specific balancing technique or extra components. Moreover, it accomplishes lossless switching in the isolated dc-dc stage, enabling a high efficiency. A 15 kW test bench is built in order to experimentally verify the inherentlybalanced voltages. The experimental tests demonstrate that the dc-link voltages are inherently-balanced (no control needed) in both transient and steady states, and that it is robust against tolerances and faulty operation. The test bench is able to provide a wide output voltage, from 200 to 900 V, and reaches a high peak efficiency of 98.2% at rated power.