Articles de revista
http://hdl.handle.net/2117/3936
20160930T20:32:41Z

Predictive control of a backtoback NPC converterbased wind power system
http://hdl.handle.net/2117/90159
Predictive control of a backtoback NPC converterbased wind power system
Calle Prado, Alejandro; Alepuz Menéndez, Salvador; Bordonau Farrerons, José; Cortés, Patricio; Rodriguez, Jose
As wind power technology points to increase power ratings, the implementation based on a permanentmagnet synchronous generator (PMSG) with a fullpower converter is expanding its market share. Multilevel converters, as for example, neutralpoint clamped (NPC) converters, are therefore well suited for this application. Predictive current control presents similar dynamic response and reference tracking than other wellestablished control methods, but working at lower switching frequencies, and providing extensive flexibility to apply either online or offline different control laws to the same plant. In this work, the predictive current control is applied to both sides of the backtoback NPC converter connecting a permanentmagnet synchronous wind power generator to the grid. DClink neutralpoint balance is achieved by means of the predictive control algorithm, which considers the redundant switching states of the backtoback NPC converter. Reduced number of commutations, current spectrum control, and compliance with the lowvoltage ridethrough (LVRT) requirement are carried out with the predictive control. The obtained experimental results confirm the suitability of the proposed control approach.
; © 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works
20160923T10:50:51Z
Calle Prado, Alejandro
Alepuz Menéndez, Salvador
Bordonau Farrerons, José
Cortés, Patricio
Rodriguez, Jose
As wind power technology points to increase power ratings, the implementation based on a permanentmagnet synchronous generator (PMSG) with a fullpower converter is expanding its market share. Multilevel converters, as for example, neutralpoint clamped (NPC) converters, are therefore well suited for this application. Predictive current control presents similar dynamic response and reference tracking than other wellestablished control methods, but working at lower switching frequencies, and providing extensive flexibility to apply either online or offline different control laws to the same plant. In this work, the predictive current control is applied to both sides of the backtoback NPC converter connecting a permanentmagnet synchronous wind power generator to the grid. DClink neutralpoint balance is achieved by means of the predictive control algorithm, which considers the redundant switching states of the backtoback NPC converter. Reduced number of commutations, current spectrum control, and compliance with the lowvoltage ridethrough (LVRT) requirement are carried out with the predictive control. The obtained experimental results confirm the suitability of the proposed control approach.

Decoupled DCLink capacitor voltage control of DCAC multilevel multileg converters
http://hdl.handle.net/2117/90151
Decoupled DCLink capacitor voltage control of DCAC multilevel multileg converters
Busquets Monge, Sergio; Griñó Cubero, Robert; Nicolás Apruzzese, Joan; Bordonau Farrerons, José
This paper studies the coupling between the capacitor voltage control loops of diodeclamped (or functionally equivalent) multilevel multileg (multiphase) dcac converters. From a complete model of the plant revealing the coupling, a simple approach consisting in multiplying the vector of control commands by a constant matrix is proposed to decouple the control problem and achieve a better controller performance. Simulation and experimental results are presented to prove the superior performance of the proposed decoupled control.
© 2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works
20160922T16:42:18Z
Busquets Monge, Sergio
Griñó Cubero, Robert
Nicolás Apruzzese, Joan
Bordonau Farrerons, José
This paper studies the coupling between the capacitor voltage control loops of diodeclamped (or functionally equivalent) multilevel multileg (multiphase) dcac converters. From a complete model of the plant revealing the coupling, a simple approach consisting in multiplying the vector of control commands by a constant matrix is proposed to decouple the control problem and achieve a better controller performance. Simulation and experimental results are presented to prove the superior performance of the proposed decoupled control.

Topological analysis of powertrains for refusecollecting vehicles based on real routes – Part II: Hybrid electric powertrain
http://hdl.handle.net/2117/90082
Topological analysis of powertrains for refusecollecting vehicles based on real routes – Part II: Hybrid electric powertrain
Soriano Alfonso, Franciso; Moreno Eguilaz, Juan Manuel; Álvarez Flórez, Jesús Andrés; Riera Colomer, Jordi
In this twopart paper, a topological analysis of powertrains for refusecollecting vehicles (RCVs) based on simulation of different architectures (internal combustion engine, hybrid electric, and hybrid hydraulic) on real routes is proposed. In this second part, three different hybrid electric powertrain architectures are proposed and modeled. These architectures are based on the use of fuel cells, ultracapacitors, and batteries. A calculation engine, which is specifically designed to estimate energy consumption, respecting the original performance as the original internal combustion engine (ICE), is presented and used for simulations and component sizing. Finally, the overall performance of the different architectures (hybrid hydraulic, taken from the first paper part, and hybrid electric, estimated in this second part) and control strategies are summarized in a fuel and energy consumption table. Based on this table, an analysis of the different architecture performance results is carried out. From this analysis, a technological evolution of these vehicles in the medium and long terms is proposed.
20160920T16:08:06Z
Soriano Alfonso, Franciso
Moreno Eguilaz, Juan Manuel
Álvarez Flórez, Jesús Andrés
Riera Colomer, Jordi
In this twopart paper, a topological analysis of powertrains for refusecollecting vehicles (RCVs) based on simulation of different architectures (internal combustion engine, hybrid electric, and hybrid hydraulic) on real routes is proposed. In this second part, three different hybrid electric powertrain architectures are proposed and modeled. These architectures are based on the use of fuel cells, ultracapacitors, and batteries. A calculation engine, which is specifically designed to estimate energy consumption, respecting the original performance as the original internal combustion engine (ICE), is presented and used for simulations and component sizing. Finally, the overall performance of the different architectures (hybrid hydraulic, taken from the first paper part, and hybrid electric, estimated in this second part) and control strategies are summarized in a fuel and energy consumption table. Based on this table, an analysis of the different architecture performance results is carried out. From this analysis, a technological evolution of these vehicles in the medium and long terms is proposed.

Topological analysis of powertrains for refusecollecting vehicles based on real routes – Part I: Hybrid hydraulic powertrain
http://hdl.handle.net/2117/90081
Topological analysis of powertrains for refusecollecting vehicles based on real routes – Part I: Hybrid hydraulic powertrain
Soriano Alfonso, Franciso; Moreno Eguilaz, Juan Manuel; Álvarez Flórez, Jesús Andrés; Riera Colomer, Jordi
In this twopart paper, a topological analysis of powertrains for refusecollecting vehicles (RCVs) based on the simulation of different architectures (internal combustion engine, hybrid electric, and hybrid hydraulic) on real routes is proposed. In this first part, a characterization of a standard route is performed, analyzing the average power consumption and the most frequent working points of an internal combustion engine (ICE) in real routes. This information is used to define alternative powertrain architectures. A hybrid hydraulic powertrain architecture is proposed and modelled. The proposed powertrain model is executed using two different control algorithms, with and without predictive strategies, with data obtained from real routes. A calculation engine (an algorithm which runs the vehicle models on real routes), is presented and used for simulations. This calculation engine has been specifically designed to analyze if the different alternative powertrain delivers the same performance of the original ICE. Finally, the overall performance of the different architectures and control strategies are summarized into a fuel and energy consumption table, which will be used in the second part of this paper to compare with the different architectures based on hybrid electric powertrain. The overall performance of the different architectures indicates that the use of a hybrid hydraulic powertrain with simple control laws can reduce the fuel consumption up to a 14 %.
20160920T15:25:11Z
Soriano Alfonso, Franciso
Moreno Eguilaz, Juan Manuel
Álvarez Flórez, Jesús Andrés
Riera Colomer, Jordi
In this twopart paper, a topological analysis of powertrains for refusecollecting vehicles (RCVs) based on the simulation of different architectures (internal combustion engine, hybrid electric, and hybrid hydraulic) on real routes is proposed. In this first part, a characterization of a standard route is performed, analyzing the average power consumption and the most frequent working points of an internal combustion engine (ICE) in real routes. This information is used to define alternative powertrain architectures. A hybrid hydraulic powertrain architecture is proposed and modelled. The proposed powertrain model is executed using two different control algorithms, with and without predictive strategies, with data obtained from real routes. A calculation engine (an algorithm which runs the vehicle models on real routes), is presented and used for simulations. This calculation engine has been specifically designed to analyze if the different alternative powertrain delivers the same performance of the original ICE. Finally, the overall performance of the different architectures and control strategies are summarized into a fuel and energy consumption table, which will be used in the second part of this paper to compare with the different architectures based on hybrid electric powertrain. The overall performance of the different architectures indicates that the use of a hybrid hydraulic powertrain with simple control laws can reduce the fuel consumption up to a 14 %.

Implicit ODE solvers with good local error control for the transient analysis of Markov models
http://hdl.handle.net/2117/89791
Implicit ODE solvers with good local error control for the transient analysis of Markov models
Suñé, Víctor; Carrasco, Juan A.
Obtaining the transient probability distribution vector of a continuoustime Markov chain (CTMC) using an implicit ordinary differential equation (ODE) solver tends to be advantageous in terms of runtime computational cost when the product of the maximum output rate of the CTMC and the largest time of interest is large. In this paper, we show that when applied to the transient analysis of CTMCs, many implicit ODE solvers are such that the linear systems involved in their steps can be solved by using iterative methods with strict control of the 1norm of the error. This allows the development of implementations of those ODE solvers for the transient analysis of CTMCs that can be more efficient and more accurate than more standard implementations.
20160909T11:04:28Z
Suñé, Víctor
Carrasco, Juan A.
Obtaining the transient probability distribution vector of a continuoustime Markov chain (CTMC) using an implicit ordinary differential equation (ODE) solver tends to be advantageous in terms of runtime computational cost when the product of the maximum output rate of the CTMC and the largest time of interest is large. In this paper, we show that when applied to the transient analysis of CTMCs, many implicit ODE solvers are such that the linear systems involved in their steps can be solved by using iterative methods with strict control of the 1norm of the error. This allows the development of implementations of those ODE solvers for the transient analysis of CTMCs that can be more efficient and more accurate than more standard implementations.

Different displacement of bioimpedance vector due to Ag/AgCl electrode effect
http://hdl.handle.net/2117/89787
Different displacement of bioimpedance vector due to Ag/AgCl electrode effect
Nescolarde Selva, Lexa Digna; Lukaski, Henry; De Lorenzo, Antonino; de Mateo Silleras, Beatriz; Redondo del Río, Maria Paz; Camina, Alicia
BACKGROUND/OBJECTIVES: Bioelectrical impedance vector analysis (BIVA) is increasingly used in clinical research to assess soft
Q2 tissue hydration. It is known that physical characteristics of electrodes, such as low intrinsic impedance, low electrode/skin contact
impedance and type of gel, affect the reliability of noninvasive bioimpedance assessments. The aim of this study was to determine
the effect of intrinsic impedance of electrode on the bioimpedance vector displacement in RXc graph.
SUBJECTS/METHODS: The intrinsic impedance is measured in nine pregelled disposable Ag/AgCl electrodes usually used for
bioimpedance measures. The BIVA method is performed on 35 healthy volunteers using a 50 kHz phasesensitive bioimpedance
analyzer (BIA 101 Anniversary) with the lowest intrinsic impedance electrode and highest. The individual bioimpedance vector is
plotted on the bivariate normal interval of reference population. The differences in the mean bioimpedance vectors obtained with
each electrode are plotted, with their 95% confidence ellipses, on the dRXc graph. The paired onesample Hotelling's T2
test is used
to compare the differences of the mean bioimpedance vectors.
RESULTS: We found large variability in intrinsic resistance (11–665 O) and reactance (0.25–2.5 O) values of the electrodes analyzed
and significant displacement (Po0.05) of bioimpedance vector positions in healthy adults according to the paired onesample
Hotelling's T2
test.
CONCLUSIONS: A robust study of all physical characteristics of commercial Ag/AgCl electrodes is necessary to reach consensus on
pregelled Ag/AgCl electrodes valid for bioimpedance measurement. This information will enable BIVA users to avoid systemic errors
when performing BIVA assessments, specifically when these measurements are used for clinical interpretations.
20160909T10:19:31Z
Nescolarde Selva, Lexa Digna
Lukaski, Henry
De Lorenzo, Antonino
de Mateo Silleras, Beatriz
Redondo del Río, Maria Paz
Camina, Alicia
BACKGROUND/OBJECTIVES: Bioelectrical impedance vector analysis (BIVA) is increasingly used in clinical research to assess soft
Q2 tissue hydration. It is known that physical characteristics of electrodes, such as low intrinsic impedance, low electrode/skin contact
impedance and type of gel, affect the reliability of noninvasive bioimpedance assessments. The aim of this study was to determine
the effect of intrinsic impedance of electrode on the bioimpedance vector displacement in RXc graph.
SUBJECTS/METHODS: The intrinsic impedance is measured in nine pregelled disposable Ag/AgCl electrodes usually used for
bioimpedance measures. The BIVA method is performed on 35 healthy volunteers using a 50 kHz phasesensitive bioimpedance
analyzer (BIA 101 Anniversary) with the lowest intrinsic impedance electrode and highest. The individual bioimpedance vector is
plotted on the bivariate normal interval of reference population. The differences in the mean bioimpedance vectors obtained with
each electrode are plotted, with their 95% confidence ellipses, on the dRXc graph. The paired onesample Hotelling's T2
test is used
to compare the differences of the mean bioimpedance vectors.
RESULTS: We found large variability in intrinsic resistance (11–665 O) and reactance (0.25–2.5 O) values of the electrodes analyzed
and significant displacement (Po0.05) of bioimpedance vector positions in healthy adults according to the paired onesample
Hotelling's T2
test.
CONCLUSIONS: A robust study of all physical characteristics of commercial Ag/AgCl electrodes is necessary to reach consensus on
pregelled Ag/AgCl electrodes valid for bioimpedance measurement. This information will enable BIVA users to avoid systemic errors
when performing BIVA assessments, specifically when these measurements are used for clinical interpretations.

Operating Principle and Performance Optimization of a ThreeLevel NPC DualActiveBridge DCDC Converter
http://hdl.handle.net/2117/89441
Operating Principle and Performance Optimization of a ThreeLevel NPC DualActiveBridge DCDC Converter
Filbà Martínez, Àlber; Busquets Monge, Sergio; Nicolás Apruzzese, Joan; Bordonau Farrerons, José
© 19822012 IEEE. Aiming to improve the performance features of conventional twolevel dualactivebridge (DAB) converters, this paper presents a threelevel neutralpointclamped (NPC) DAB dcdc converter. A general modulation pattern is initially defined, the dclink capacitor voltage balancing is analyzed in detail, and a proper balancing control is designed. Then, a set of decoupled optimization problems is formulated as a function of the available modulation degrees of freedom to minimize the predominant converter losses. Finally, a simple and practical specific modulation strategy is provided, resembling the optimum solutions. The good performance of the proposed threelevel NPC DAB converter operated with the proposed modulation strategy and voltage balancing control is verified through simulation and experiments. The capacitor voltage balancing can be guaranteed for all operating conditions. In addition, it is concluded that the multilevel topology provides benefits compared with the conventional twolevel DAB converter.
20160901T09:06:19Z
Filbà Martínez, Àlber
Busquets Monge, Sergio
Nicolás Apruzzese, Joan
Bordonau Farrerons, José
© 19822012 IEEE. Aiming to improve the performance features of conventional twolevel dualactivebridge (DAB) converters, this paper presents a threelevel neutralpointclamped (NPC) DAB dcdc converter. A general modulation pattern is initially defined, the dclink capacitor voltage balancing is analyzed in detail, and a proper balancing control is designed. Then, a set of decoupled optimization problems is formulated as a function of the available modulation degrees of freedom to minimize the predominant converter losses. Finally, a simple and practical specific modulation strategy is provided, resembling the optimum solutions. The good performance of the proposed threelevel NPC DAB converter operated with the proposed modulation strategy and voltage balancing control is verified through simulation and experiments. The capacitor voltage balancing can be guaranteed for all operating conditions. In addition, it is concluded that the multilevel topology provides benefits compared with the conventional twolevel DAB converter.

Comparison of two PV array models for the simulation of PV systems using five different algorithms for the parameters identification
http://hdl.handle.net/2117/89279
Comparison of two PV array models for the simulation of PV systems using five different algorithms for the parameters identification
Kichou, Sofiane; Silvestre Bergés, Santiago; Guglielminotti, Letizia; MoraLópez, Llanos; MuñozCerón, Emilio
Simulation is of primal importance in the prediction of the produced power and automatic fault detection in PV gridconnected systems (PVGCS). The accuracy of simulation results depends on the models used for main components of the PV system, especially for the PV module. The present paper compares two PV array models, the fiveparameter model (5PM) and the Sandia Array Performance Model (SAPM). Five different algorithms are used for estimating the unknown parameters of both PV models in order to see how they affect the accuracy of simulations in reproducing the outdoor behavior of three PVGCS. The arrays of the PVGCS are of three different PV module technologies: Crystalline silicon (cSi), amorphous silicon (aSi:H) and micromorph silicon (aSi:H/µcSi:H).
The accuracy of PV module models based on the five algorithms is evaluated by means of the Route Mean Square Error (RMSE) and the Normalized Mean Absolute Error (NMAE), calculated for different weather conditions (clear sky, semicloudy and cloudy days). For both models considered in this study, the best accuracy is obtained from simulations using the estimated values of unknown parameters delivered by the ABC algorithm. Where, the maximum error values of RMSE and NMAE stay below 6.61% and 2.66% respectively.
20160727T14:04:55Z
Kichou, Sofiane
Silvestre Bergés, Santiago
Guglielminotti, Letizia
MoraLópez, Llanos
MuñozCerón, Emilio
Simulation is of primal importance in the prediction of the produced power and automatic fault detection in PV gridconnected systems (PVGCS). The accuracy of simulation results depends on the models used for main components of the PV system, especially for the PV module. The present paper compares two PV array models, the fiveparameter model (5PM) and the Sandia Array Performance Model (SAPM). Five different algorithms are used for estimating the unknown parameters of both PV models in order to see how they affect the accuracy of simulations in reproducing the outdoor behavior of three PVGCS. The arrays of the PVGCS are of three different PV module technologies: Crystalline silicon (cSi), amorphous silicon (aSi:H) and micromorph silicon (aSi:H/µcSi:H).
The accuracy of PV module models based on the five algorithms is evaluated by means of the Route Mean Square Error (RMSE) and the Normalized Mean Absolute Error (NMAE), calculated for different weather conditions (clear sky, semicloudy and cloudy days). For both models considered in this study, the best accuracy is obtained from simulations using the estimated values of unknown parameters delivered by the ABC algorithm. Where, the maximum error values of RMSE and NMAE stay below 6.61% and 2.66% respectively.

Integration of GMR sensors with different technologies
http://hdl.handle.net/2117/89277
Integration of GMR sensors with different technologies
Cubells Beltrán, M. Dolores; Reig Escriva, Abilio Càndid; Madrenas Boadas, Jordi; De Marcellis, A.; Santos, Joana; Cardoso, Susana; Freitas, P.P.
Less than thirty years after the giant magnetoresistance (GMR) effect was described, GMR sensors are the preferred choice in many applications demanding the measurement of low magnetic fields in small volumes. This rapid deployment from theoretical basis to market and stateoftheart applications can be explained by the combination of excellent inherent properties with the feasibility of fabrication, allowing the real integration with many other standard technologies. In this paper, we present a review focusing on how this capability of integration has allowed the improvement of the inherent capabilities and, therefore, the range of application of GMR sensors. After briefly describing the phenomenological basis, we deal on the benefits of low temperature deposition techniques regarding the integration of GMR sensors with flexible (plastic) substrates and preprocessed CMOS chips. In this way, the limit of detection can be improved by means of bettering the sensitivity or reducing the noise. We also report on novel fields of application of GMR sensors by the recapitulation of a number of cases of success of their integration with different heterogeneous complementary elements. We finally describe three fully functional systems, two of them in the biotechnology world, as the proof of how the integrability has been instrumental in the meteoric development of GMR sensors and their applications.
20160727T13:45:48Z
Cubells Beltrán, M. Dolores
Reig Escriva, Abilio Càndid
Madrenas Boadas, Jordi
De Marcellis, A.
Santos, Joana
Cardoso, Susana
Freitas, P.P.
Less than thirty years after the giant magnetoresistance (GMR) effect was described, GMR sensors are the preferred choice in many applications demanding the measurement of low magnetic fields in small volumes. This rapid deployment from theoretical basis to market and stateoftheart applications can be explained by the combination of excellent inherent properties with the feasibility of fabrication, allowing the real integration with many other standard technologies. In this paper, we present a review focusing on how this capability of integration has allowed the improvement of the inherent capabilities and, therefore, the range of application of GMR sensors. After briefly describing the phenomenological basis, we deal on the benefits of low temperature deposition techniques regarding the integration of GMR sensors with flexible (plastic) substrates and preprocessed CMOS chips. In this way, the limit of detection can be improved by means of bettering the sensitivity or reducing the noise. We also report on novel fields of application of GMR sensors by the recapitulation of a number of cases of success of their integration with different heterogeneous complementary elements. We finally describe three fully functional systems, two of them in the biotechnology world, as the proof of how the integrability has been instrumental in the meteoric development of GMR sensors and their applications.

Characterization and modeling of organic thinfilm transistors based piconjugated small molecule tetraphenyldibenzoperiflanthene: Effects of channel length
http://hdl.handle.net/2117/89098
Characterization and modeling of organic thinfilm transistors based piconjugated small molecule tetraphenyldibenzoperiflanthene: Effects of channel length
boukhili, W.; Mahdouani, M.; Bourguiga, R.; Puigdollers i González, Joaquim
Ptype organic thin film transistors (OTFTs) with different channel lengths have been fabricated and characterized by thermal evaporation using the small tetraphenyldibenzoperiflanthene (DBP) as an active material on Si/SiO2 substrate. The influence of the channel length on the electrical performance of DBP based organic thin film transistors (DBPTFTs) prepared with bottom gatebottom contact in the linear and saturation regimes was systematically examined in this work. All devices showed a significant increase in the output and transfer drain current as the channel lengths were decreased in the linear and saturation regimes. We have reported the variation of the electrical parameters such as transconductance (g(m)), field effect mobility (mu(lin) and mu(sat)), contacts and total resistances (RC and RT), threshold voltage (Vth), total trap density (Ntrap), subthreshold slope (SS), the interface trap density (Dit), turnon voltage (Von) and the ratio current (Ion/Ioff) by channel length variation which are extracted from the experimental electrical data currentvoltage of DBPTFTs. We found that the field effect mobility is extremely dependent on the channel length dimensions. We also show that for smaller channel length, it results in a good mobility and a good ratio current of the DBPTFTs with a short channel length (good saturation mobility and current ratio mu(sat.max) = 3 x 10(2) cm(2) V1 s(1),1.6 x 10(4), respectively, for L = 2.5 mu m). The developed model shows a good agreement with the measured data for all values of channel lengths (L).
20160722T17:33:12Z
boukhili, W.
Mahdouani, M.
Bourguiga, R.
Puigdollers i González, Joaquim
Ptype organic thin film transistors (OTFTs) with different channel lengths have been fabricated and characterized by thermal evaporation using the small tetraphenyldibenzoperiflanthene (DBP) as an active material on Si/SiO2 substrate. The influence of the channel length on the electrical performance of DBP based organic thin film transistors (DBPTFTs) prepared with bottom gatebottom contact in the linear and saturation regimes was systematically examined in this work. All devices showed a significant increase in the output and transfer drain current as the channel lengths were decreased in the linear and saturation regimes. We have reported the variation of the electrical parameters such as transconductance (g(m)), field effect mobility (mu(lin) and mu(sat)), contacts and total resistances (RC and RT), threshold voltage (Vth), total trap density (Ntrap), subthreshold slope (SS), the interface trap density (Dit), turnon voltage (Von) and the ratio current (Ion/Ioff) by channel length variation which are extracted from the experimental electrical data currentvoltage of DBPTFTs. We found that the field effect mobility is extremely dependent on the channel length dimensions. We also show that for smaller channel length, it results in a good mobility and a good ratio current of the DBPTFTs with a short channel length (good saturation mobility and current ratio mu(sat.max) = 3 x 10(2) cm(2) V1 s(1),1.6 x 10(4), respectively, for L = 2.5 mu m). The developed model shows a good agreement with the measured data for all values of channel lengths (L).