Open Access
Modeling of small wind turbines based on PMSG with diode bridge for sensorless maximum power tracking
(Elsevier, 2013) Urtasun Erburu, Andoni; Sanchis Gúrpide, Pablo; San Martín Biurrun, Idoia; López Taberna, Jesús; Marroyo Palomo, Luis; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
The Permanent Magnet Synchronous Generator (PMSG) with diode bridge is frequently used in small Wind Energy Conversion Systems (WECS). This configuration is robust and cheap, and therefore suitable for small WECS. In order to achieve Maximum Power Point Tracking (MPPT) with no mechanical sensors, it is possible to impose the relationship between the DC voltage and the DC current on the optimum operating points. However, this relationship is difficult to calculate theoretically since the whole system is involved. In fact, as there is no model of the whole system in the literature, the optimum curve IL*(Vdc) is obtained with experimental tests or simulations. This paper develops an accurate model of the whole WECS, thereby making it possible to relate the electrical variables to the mechanical ones. With this model, it is possible to calculate the optimum curve IL*(Vdc) from commonly-known system parameters and to control the system from the DC side. Experimental results validate the theoretical analysis and show that maximum power is extracted for actual wind speed profiles.
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
Characterization and capacity dispersion of lithium-ion second-life batteries from electric vehicles
(IEEE, 2019) Braco Sola, Elisa; San Martín Biurrun, Idoia; Sanchis Gúrpide, Pablo; Ursúa Rubio, Alfredo; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación; Gobierno de Navarra / Nafarroako Gobernua
Nowadays, electric vehicle batteries reutilization is considered such as a feasible alternative to recycling, as it allows to benefit from their remaining energy and to enlarge their lifetime. Stationary applications as self-consumption or isolated systems support are examples of possible second life uses for these batteries. However, the modules that compose these batteries have very heterogeneous properties, and therefore condition their performance. This paper aims to characterize and analyze the existing capacity dispersion of Nissan Leaf modules that have reached the end of their lifetime on their original application and of new modules of this Electric Vehicle, in order to establish a comparison between them.
Open Access
Health indicator selection for state of health estimation of second-life lithium-ion batteries under extended ageing
(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
Nowadays, the economic viability of second-life (SL) Li-ion batteries from electric vehicles is still uncertain. Degradation assessment optimization is key to reduce costs in SL market not only at the repurposing stage, but also during SL lifetime. As an indicator of the ageing condition of the batteries, state of health (SOH) is currently a major research topic, and its estimation has emerged as an alternative to traditional characterization tests. In an initial stage, all SOH estimation methods require the extraction of health indicators (HIs), which influence algorithm complexity and on-board implementation. Nevertheless, a literature gap has been identified in the assessment of HIs for reused Li-ion batteries. This contribution targets this issue by analysing 58 HIs obtained from incremental capacity analysis, partial charging, constant current and constant voltage stage, and internal resistance. Six Nissan Leaf SL modules were aged under extended cycling testing, covering a SOH range from 71.2 % to 24.4 %. Results show that the best HI at the repurposing stage was obtained through incremental capacity analysis, with 0.2 % of RMSE. During all SL use, partial charge is found to be the best method, with less than 2.0 % of RMSE. SOH is also estimated using the best HI and different algorithms. Linear regression is found to overcome more complex options with similar estimation accuracy and significantly lower computation times. Hence, the importance of analysing and selecting a good SL HI is highlighted, given that this made it possible to obtain accurate SOH estimation results with a simple algorithm.
Open Access
Analysis and modelling of calendar ageing in second-life lithium-ion batteries from electric vehicles
(IEEE, 2022) 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; Gobierno de NAVARRA / Nafarroako Gobernua
The reuse of Li-ion batteries from electric vehicles is a promising alternative to recycling nowadays. However, the technical and economic viability of these second-life (SL) batteries is not yet clear. Degradation assessment plays a key role not only to analyse the impact of ageing factors in reused batteries, but also to quantify their durability. In this context, this contribution aims to analyse calendar ageing behaviour in SL cells. 16 reused Nissan Leaf modules are aged during 750 days under three temperatures and four State of Charge (SOC), covering a State of Health range from 72.2 % to 13 %. The impact of temperature and SOC as stress factors is firstly analysed, concluding that their increase accelerates ageing. Temperature rise is found to have a major impact, accelerating up to 27 times capacity fade and almost 6 times resistance increase when compared to light ageing conditions, while increasing SOC nearly doubles ageing rates. The worst ageing case is found to be the combination of 60 ◦C and 66 % of SOC. Regarding degradation trends, they are proven to be constant during all SL lifetime. This work also proposes and validates a calendar ageing model for SL cells. Accuracy of validation results show a fitting Rsq of 0.9941 in capacity fade and 0.9557 in resistance increase, thereby tracking the heterogeneous degradation of the SL cells under calendar ageing.
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-based energy storage for a distributed generation system
(Spanish Hydrogen Association, 2016) San Martín Biurrun, Idoia; Berrueta Irigoyen, Alberto; Ursúa Rubio, Alfredo; Sanchis Gúrpide, Pablo; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC
One of the most typical distributed generation systems are electrical microgrid, which consist on small electrical grids, generally connected to the main grid, with a decentralized management structure. Electrical microgrids allow higher renewable energy integration in the grid, achieving a cost decrease and improving the grid quality [1]. These mi- crogrids incorporate renewable generation systems and energy consumers. Moreover, they have storage systems to balance generation and consumption as well as the exchanged power with the main grid. Traditionally, lead-acid batter- ies have been used in microgrids. However, these batteries have some drawbacks, being the most important its poor performance in partial state of charge, which is critical for a microgrid. A suitable option for the storage system is hy- drogen technology. These systems have high energy density, which makes the storage system able to assume seasonal variability of renewable resources. This paper proposes a sizing methodology for storage systems based on hydrogen for grid-tied electrical microgrids. This methodology optimizes the relationship between the storage system size and the consumption of grid power.
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.
Open Access
Lithium-ion second-life batteries: aging modeling and experimental validation
(IEEE, 2024-08-30) Pérez Ibarrola, Ane; San Martín Biurrun, Idoia; Sanchis Gúrpide, Pablo; Ursúa Rubio, Alfredo; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, PJUPNA2023-11380; Gobierno de Navarra / Nafarroako Gobernua
Re-utilizing lithium-ion batteries from electric vehicles reduces their environmental impact. To ensure their optimal sizing and safe use, identifying the current state of the battery and predicting its remaining useful life is essential. This work analyzes the degradation mechanisms involved and proposes an aging model that utilizes a semi-empirical approach to accurately reproduce the battery's state of health within a range of 75-45 %. Calendar aging includes dependencies on temperature and state of charge while cycling aging is modeled based on depth of discharge, medium SOC, temperature, and Crate. The model is validated against experimental data from 14 LMO/LNO cells previously used in actual Nissan Leaf vehicles and an RMSE bellow 2.5 % is achieved in every case.
Open Access
Integrated lithium-ion battery model and experimental validation of a second-life prototype
(IEEE, 2023-08-31) Pérez Ibarrola, Ane; San Martín Biurrun, Idoia; 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
A battery model predicts the battery performance, which can be a useful tool for optimizing battery design and preventing unsafe operation. This becomes especially significant in second-life batteries where the cells have already endured degradation and predicting the lifetime becomes challenging. The assessment of physical phenomena is often performed individually, but the overall battery behavior depends on their interaction. For this purpose, an integrated battery model is developed. Equivalent electric circuits are interconnected to represent the electrochemical reactions, thermodynamic phenomena, and heat transfer mechanisms of the battery. To consider cell degradation, calendar and cycling aging were represented using a semi-empirical model. A battery management system is included to oversee and remain within the safe limits of battery voltage, temperature, and current. Additionally, a passive cell balancing distributes charge evenly. The integrated model is applied to a second-life battery prototype with a nominal capacity and power of 45 Ah and 4 kW, respectively. Its performance is validated with constant current and power cycles, as well as in a microgrid with photovoltaic generation under a self-consumption profile. The model accurately reproduces experimental results of battery power, voltage, temperature, and state of charge.