Open Access
Lithium-ion battery model and experimental validation
(2015) Berrueta Irigoyen, Alberto; Irigaray, Víctor; Sanchis Gúrpide, Pablo; Ursúa Rubio, Alfredo; Ingeniaritza Elektrikoa eta Elektronikoa; Institute of Smart Cities - ISC; Ingeniería Eléctrica y Electrónica
A simple battery model is useful for: Sizing of the storage system for a particular application; Designing other elements connected to the battery; Managing the storage system operation. This poster consists on: Tests to characterize a lithium-ion battery at Ta=23 ⁰C. Methodology to fit the parameters of the battery model; Parameter trends related to the state of charge; Experimental validation and model accuracy.
Open Access
Static and dynamic characterization of a supercapacitor
(2014) Berrueta Irigoyen, Alberto; San Martín Biurrun, Idoia; Ursúa Rubio, Alfredo; Sanchis Gúrpide, Pablo; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
Supercapacitors (SCs) have recently received a major boost as a result of the development of multiple applications, such as the electric vehicle and electric microgrids. Storage systems consisting of SCs combined with batteries or fuel cells have been proposed in multiple applications. Since SCs store energy as an electric field, they are able to efficiently manage high power and high frequency charge‐discharge cycles. This ability to handle high power in a wide frequency range grants them a wide advantage against other energy‐storage technologies. A static and dynamic characterization of the Maxwell SC BMOD0083 has been accomplished in this study.
Open Access
Hydrogen-lithium energy storage for a stand-alone microgrid
(2016) Berrueta Irigoyen, Alberto; San Martín Biurrun, Idoia; Sanchis Gúrpide, Pablo; Ursúa Rubio, Alfredo; Ingeniaritza Elektrikoa eta Elektronikoa; Institute of Smart Cities - ISC; Ingeniería Eléctrica y Electrónica
Sizing of the storage system for a stand-alone application: Satisfaction of technical requirements; Based on real data from an experimental microgrid; Long lifetime; Lowest price
Open Access
Impact of micro-cycles on the lifetime of lithium-ion batteries - EIS analysis
(IEEE, 2024-07-30) Nováková, Katerina; Berrueta Irigoyen, Alberto; Soto Cabria, Adrián; Sanchis Gúrpide, Pablo; Ursúa Rubio, Alfredo; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC; Gobierno de Navarra / Nafarroako Gobernua
Experimental studies of lithium-ion batteries are very often based only on deep charge and discharge cycles. However, these test profiles do not fully reflect the actual operation of the battery in an electric vehicle or in stationary applications, where the battery is not only loaded during the main charging and discharging profiles, but it is also stressed by the current throughput caused by renewable power fluctuations or by auxiliary services. These cycles, which are superimposed to the main charge and discharge processes and have a depth of discharge not exceeding 2%, are called micro-cycles. Although there are several simulation studies that attempt to capture this issue, there is still no comprehensive experimental study that has the phenomena that occur during micro-cycling. This paper presents an experimental analysis of micro-cycles, providing a detailed view of the different processes taking place in the battery during aging, by means of a detailed analysis of the results from electrochemical impedance spectroscopy (EIS). By studying the single electrochemical processes in detail, this paper explains the benefits of micro-cycling in terms of extending the lifetime of the battery.
Open Access
Distributed opportunistic wireless mapping system towards smart city service provision
(IEEE, 2021) Villadangos Alonso, Jesús; Falcone Lanas, Francisco; López Martín, Antonio; Astrain Escola, José Javier; Sanchis Gúrpide, Pablo; Matías Maestro, Ignacio; Estatistika, Informatika eta Matematika; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Estadística, Informática y Matemáticas; Ingeniería Eléctrica, Electrónica y de Comunicación
The knowledge of wireless signal distribution within an urban scenario can provide useful information to users as well as to enhance connectivity and device operation or to perform municipal logistics based on crowd density and user mobility patterns. In this work, a distributed wireless mapping system, based on a combination of opportunistic nodes such as smartphones which map geolocated WiFi access point connection and received power levels, and a cloud-based information gathering architecture is described. The proposed system has been tested in the framework of the Smart City platform of the city of Pamplona, providing signal distribution heat maps, which can be used for multiple municipal services.
Open Access
Experimental assessment of first- and second-life electric vehicle batteries: performance, capacity dispersion, and aging
(IEEE, 2021) Braco Sola, Elisa; San Martín Biurrun, Idoia; Berrueta Irigoyen, Alberto; Sanchis Gúrpide, Pablo; Ursúa Rubio, Alfredo; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa; Gobierno de Navarra / Nafarroako Gobernua
Nowadays, the reuse of electric vehicle batteries is considered to be a feasible alternative to recycling, as it allows them to benefit from their remaining energy capacity and to enlarge their lifetime. Stationary applications, such as self-consumption or off-grid systems support, are examples of second-life (SL) uses for retired batteries. However, reused modules that compose these batteries have heterogeneous properties, which limit their performance. This article aims to assess the influence of degradation in modules from electric vehicles, covering three main aspects: performance, capacity dispersion, and extended SL behavior. First, a complete characterization of new and reused modules is carried out, considering three temperatures and three discharge rates. In the second stage, intra- and intermodule capacity dispersions are evaluated with new and reused samples. Finally, the behavior during SL is also analyzed, through an accelerated cycling test so that the evolution of capacity and dispersion are assessed. Experimental results show that the performance of reused modules is especially undermined at low temperatures and high current rates, as well as in advanced stages of aging. The intramodule dispersion is found to be similar in reused and new samples, while the intermodule differences are nearly four times greater in SL.
Open Access
On the testing, characterization, and evaluation of PV inverters and dynamic MPPT performance under real varying operating conditions
(Wiley, 2007) Sanchis Gúrpide, Pablo; López Taberna, Jesús; Ursúa Rubio, Alfredo; Gubía Villabona, Eugenio; Marroyo Palomo, Luis; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Gobierno de Navarra / Nafarroako Gobernua
The increasing number of photovoltaic inverters that are coming on to the PV marketstresses the need to carry out a dynamic characterization of these elements and theirmaximum power point tracking (MPPT) algorithms under real operating conditions.In order to make these conditions repeatable at the laboratory, PV array simulatorsare used. However, actual simulators, including the commercial simulators, recreateonly a single or small set of PV array characteristic curves in which quite commonlytheoretical calculations are included in order to simulate irradiance and temperatureartificial variations. This is far from being a recreation of the real and long dynamicbehavior of a PVarray or generator. The testing and evaluation of the performance ofPV inverters and MPPT algorithms has to be carried out when the PV system movesdynamically according to real operating conditions, including processes such asrapidly changing atmospheric conditions, partial shadows, dawn, and nightfall. Thispaper tries to contribute to the analysis of this problem by means of an electronicsystem that both measures the real evolution of the characteristic curves of PVarraysat outdoor operation and then recreates them at the laboratory to test PV inverters.This way the equipment can highlight the different performances of PV inverters andMPPT techniques when they operate under real operating conditions. As an example,two commercial inverters are tested and analyzed under the recreated behavior of aPV generator during 2 singular days that include processes of partial shading and fastirradiance variations.
Open Access
State of health estimation of second-life lithium-ion batteries under real profile operation
(Elsevier, 2022) Braco Sola, Elisa; San Martín Biurrun, Idoia; Sanchis Gúrpide, Pablo; Ursúa Rubio, Alfredo; Stroe, Daniel-Ioan; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación; Gobierno de Navarra / Nafarroako Gobernua; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
The economic viability of second-life (SL) Li-ion batteries from electric vehicles (EVs) is still uncertain nowadays. Assessing the internal state of reused cells is key not only at the repurposing stage but also during their SL operation. As an alternative of the traditional capacity tests used to this end, the estimation of State of Health (SOH) allows to reduce the testing time and the need of equipment, thereby reinforcing the economic success of SL batteries. However, the estimation of SOH in real SL operation has been rarely analysed in literature. This contribution aims thus to cover this gap, by focusing on the experimental assessment of SOH estimation in reused modules from Nissan Leaf EVs under two SL scenarios: a residential household with self-consumption and a fast charge station for EVs. By means of partial charge and experimental data from cycling and calendar ageing tests, accuracy and robustness of health indicators is firstly assessed. Then, SOH estimation is carried out using real profiles, covering a SOH range from 91.3 to 31%. Offline assessment led to RMSE values of 0.6% in the residential profile and 0.8% in the fast charge station, with a reduction in testing times of 85% compared to a full capacity test. In order to avoid the interruption of battery operation, online assessment in profiles was also analysed, obtaining RMSE values below 1.3% and 3.6% in the residential and charging station scenarios, respectively. Therefore, the feasibility of SOH estimation in SL profiles is highlighted, as it allows to get accurate results reducing testing times or even without interrupting normal operation.
Open Access
Fast capacity and internal resistance estimation method for second-life batteries from electric vehicles
(Elsevier, 2023) Braco Sola, Elisa; San Martín Biurrun, Idoia; Sanchis Gúrpide, Pablo; Ursúa Rubio, Alfredo; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
The success of second-life (SL) Li-ion batteries from electric vehicles is still conditioned by their technical and economic viability. The knowledge of the internal parameters of retired batteries at the repurposing stage is key to ensure their adequate operation and to enlarge SL lifetime. However, traditional characterization methods require long testing times and specific equipment, which result in high costs that may jeopardize the economic viability of SL. In the seek of optimizing the repurposing stage, this contribution proposes a novel fast characterization method that allows to estimate capacity and internal resistance at various state of charge for reused cells, modules and battery packs. Three estimation models are proposed. The first of them is based on measurements of AC resistance, the second on DC resistance and the third combines both resistance types. These models are validated in 506 cells, 203 modules and 3 battery packs from different Nissan Leaf vehicles. The results achieved are satisfactory, with mean absolute percentage errors (MAPE) below 2.5% at cell and module level in capacity prediction and lower than 2.4% in resistance estimation. Considering battery pack level, MAPE is below 4.2% and 1.8% in capacity and resistance estimation respectively. With the proposed method, testing times are reduced from more than one day to 2 min per cell, while energy consumption is lowered from 1.4 kWh to 1 Wh. In short, this study contributes to the reduction of repurposing procedures and costs, and ultimately to the success of SL batteries business model.
Open Access
Supercapacitors: electrical characteristics, modelling, applications and future trends
(IEEE, 2019) Berrueta Irigoyen, Alberto; Ursúa Rubio, Alfredo; San Martín Biurrun, Idoia; Eftekhari, Ali; Sanchis Gúrpide, Pablo; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación; Gobierno de Navarra / Nafarroako Gobernua, PI020 RENEWABLE-STORAGE
Energy storage systems are playing an increasingly important role in a variety of applications, such as electric vehicles or grid-connected systems. In this context, supercapacitors (SCs) are gaining ground due to their high power density, good performance and long maintenance-free lifetime. For this reason, SCs are a hot research topic, and several papers are being published on material engineering, performance characterization, modelling and post-mortem analysis. A compilation of the most important millstones on this topic is essential to keep researchers on related fields updated about new potentials of this technology. This review paper covers recent research aspects and applications of SCs, highlighting the relationship between material properties and electrical characteristics. It begins with an explanation of the energy storage mechanisms and materials used by SCs. Based on these materials, the SCs are classified, their key features are summarised, and their electrochemical characteristics are related to electrical performance. Given the high interest in system modelling and the large number of papers published on this topic, modelling techniques are classified, explained and compared, addressing their strengths and weaknesses, and the experimental techniques used to measure the modelled properties are described. Finally, the market sectors in which SCs are successfully used, as well as their growth expectations are analysed. The analysis presented herein gives account of the expansion that SC market is currently undergoing and identifies the most promising research trends on this field.