ACES  Control Avançat de Sistemes d'Energia
http://hdl.handle.net/2117/114
Thu, 16 Nov 2017 06:17:44 GMT
20171116T06:17:44Z
ACES  Control Avançat de Sistemes d'Energia
http://upcommons.upc.edu/bitstream/id/217/aces.gif
http://hdl.handle.net/2117/114

Identification of PEM fuel cells based on support vector regression and orthonormal bases
http://hdl.handle.net/2117/110513
Identification of PEM fuel cells based on support vector regression and orthonormal bases
Feroldi, Diego Hernan; Gómez, Juan Carlos; Roda Serrat, Vicente
Polymer Electrolyte Membrane Fuel Cells (PEMFC) are efficient devices that convert the chemical energy of the reactants in electricity. In this type of fuel cells, the performance of the air supply system is fundamental to improve their efficiency. An accurate mathematical model representing the air filling dynamics for a wide range of operating points is then necessary for control design and analysis. In this paper, a new Wiener model identification method based on Support Vector (SV) Regression and orthonormal bases is introduced and used to estimate a nonlinear dynamical model for the air supply system of a laboratory PEMFC from experimental data. The method is experimentally validated using a PEMFC system based on a ZB 8cell stack with Nafion 115 membrane electrode assemblies
© 20xx 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.
Mon, 13 Nov 2017 17:22:39 GMT
http://hdl.handle.net/2117/110513
20171113T17:22:39Z
Feroldi, Diego Hernan
Gómez, Juan Carlos
Roda Serrat, Vicente
Polymer Electrolyte Membrane Fuel Cells (PEMFC) are efficient devices that convert the chemical energy of the reactants in electricity. In this type of fuel cells, the performance of the air supply system is fundamental to improve their efficiency. An accurate mathematical model representing the air filling dynamics for a wide range of operating points is then necessary for control design and analysis. In this paper, a new Wiener model identification method based on Support Vector (SV) Regression and orthonormal bases is introduced and used to estimate a nonlinear dynamical model for the air supply system of a laboratory PEMFC from experimental data. The method is experimentally validated using a PEMFC system based on a ZB 8cell stack with Nafion 115 membrane electrode assemblies

Combined heat and power using high temperature proton exchange membrane fuel cells for comfort applications
http://hdl.handle.net/2117/110267
Combined heat and power using high temperature proton exchange membrane fuel cells for comfort applications
Sanz i López, Víctor; Costa Castelló, Ramon; Batlle Arnau, Carles
Global concerns about nowadays’ energy shortage problems as well as climate change eects have encouraged alternatives to classical energy sources such as fossil fuels and nuclear power plants. In this context, combined heat and power is presented as a useful option due to its ability of generating both electrical and thermal energy more eciently than conventional methods. Regarding this, high temperature proton exchange membrane fuel cells are not only a reliable way of implementing combined heat and power systems, but also a better solution in terms of energy conversion eciency and greenhouse gases emissions reduction. Therefore, high temperature proton exchange membrane fuel cells are being installed around the world and policies encouraging its utilisation are being promoted.
Fri, 10 Nov 2017 13:00:50 GMT
http://hdl.handle.net/2117/110267
20171110T13:00:50Z
Sanz i López, Víctor
Costa Castelló, Ramon
Batlle Arnau, Carles
Global concerns about nowadays’ energy shortage problems as well as climate change eects have encouraged alternatives to classical energy sources such as fossil fuels and nuclear power plants. In this context, combined heat and power is presented as a useful option due to its ability of generating both electrical and thermal energy more eciently than conventional methods. Regarding this, high temperature proton exchange membrane fuel cells are not only a reliable way of implementing combined heat and power systems, but also a better solution in terms of energy conversion eciency and greenhouse gases emissions reduction. Therefore, high temperature proton exchange membrane fuel cells are being installed around the world and policies encouraging its utilisation are being promoted.

Optimal power flow for resistive DC networks: a porthamiltonian approach
http://hdl.handle.net/2117/110148
Optimal power flow for resistive DC networks: a porthamiltonian approach
Benedito Benet, Ernest; del Puerto Flores, Dunstano; Dòria Cerezo, Arnau; Scherpen, Jacquelien
This paper studies the optimal power flow problem for resistive DC networks. The gradient method algorithm is written in a portHamiltonian form and the stability of the resulting dynamics is studied. Stability conditions are provided for general cyclic networks and a solution, when these conditions fail, is proposed. In addition, the results are exemplified by means of numerical simulations.
Wed, 08 Nov 2017 13:10:59 GMT
http://hdl.handle.net/2117/110148
20171108T13:10:59Z
Benedito Benet, Ernest
del Puerto Flores, Dunstano
Dòria Cerezo, Arnau
Scherpen, Jacquelien
This paper studies the optimal power flow problem for resistive DC networks. The gradient method algorithm is written in a portHamiltonian form and the stability of the resulting dynamics is studied. Stability conditions are provided for general cyclic networks and a solution, when these conditions fail, is proposed. In addition, the results are exemplified by means of numerical simulations.

A local stability condition for dc grids with constant power loads
http://hdl.handle.net/2117/110130
A local stability condition for dc grids with constant power loads
Arocas Pérez, José; Griñó Cubero, Robert
Currently, there are an increasing number of power electronics converters in electrical grids, performing the most diverse tasks, but most of them, work as constant power loads (CPLs). This work presents a sufficient condition for the local stability of dc linear timeinvariant circuits with constant power loads for all the possible equilibria (depending on the drained power) of the systems. The condition is shown as a method with successive steps that should be met. Its main step is expressed as a linear matrix inequality test which is important for easiness of verification reasons. The method is illustrated with two examples: a singleport RLC circuit connected to a CPL and a twoport linear dc circuit connected to two CPLs.
Wed, 08 Nov 2017 09:02:59 GMT
http://hdl.handle.net/2117/110130
20171108T09:02:59Z
Arocas Pérez, José
Griñó Cubero, Robert
Currently, there are an increasing number of power electronics converters in electrical grids, performing the most diverse tasks, but most of them, work as constant power loads (CPLs). This work presents a sufficient condition for the local stability of dc linear timeinvariant circuits with constant power loads for all the possible equilibria (depending on the drained power) of the systems. The condition is shown as a method with successive steps that should be met. Its main step is expressed as a linear matrix inequality test which is important for easiness of verification reasons. The method is illustrated with two examples: a singleport RLC circuit connected to a CPL and a twoport linear dc circuit connected to two CPLs.

Canonical realization of (2+1)dimensional BondiMetznerSachs symmetry
http://hdl.handle.net/2117/108683
Canonical realization of (2+1)dimensional BondiMetznerSachs symmetry
Batlle Arnau, Carles; Campello, Víctor; Gomis Torné, Joaquin
We construct canonical realizations of the (2+1)dimensional BondiMetznerSachs (bms3) algebra as symmetry algebras of a free KleinGordon (KG) field in 2+1 dimensions for both massive and massless cases. We consider two types of realizations, one on shell, written in terms of the Fourier modes of the scalar field, and the other off shell, with nonlocal transformations written in terms of the KG field and its momenta. These realizations contain both supertranslations and superrotations, for which we construct the corresponding Noether charges.
Fri, 13 Oct 2017 11:10:35 GMT
http://hdl.handle.net/2117/108683
20171013T11:10:35Z
Batlle Arnau, Carles
Campello, Víctor
Gomis Torné, Joaquin
We construct canonical realizations of the (2+1)dimensional BondiMetznerSachs (bms3) algebra as symmetry algebras of a free KleinGordon (KG) field in 2+1 dimensions for both massive and massless cases. We consider two types of realizations, one on shell, written in terms of the Fourier modes of the scalar field, and the other off shell, with nonlocal transformations written in terms of the KG field and its momenta. These realizations contain both supertranslations and superrotations, for which we construct the corresponding Noether charges.

Nonrelativistic BondiMetznerSachs algebra
http://hdl.handle.net/2117/108665
Nonrelativistic BondiMetznerSachs algebra
Batlle Arnau, Carles; Delmastro, Diego; Gomis Torné, Joaquin
We construct two possible candidates for nonrelativistic bms(4) algebra in four spacetime dimensions by contracting the original relativistic bms(4) algebra. bms(4) algebra is infinitedimensional and it contains the generators of the Poincare algebra, together with the socalled supertranslations. Similarly, the proposed nrbms(4) algebras can be regarded as two infinitedimensional extensions of the Bargmann algebra. We also study a canonical realization of one of these algebras in terms of the Fourier modes of a free Schrodinger field, mimicking the canonical realization of relativistic bms(4) algebra using a free KleinGordon field.
Wed, 11 Oct 2017 16:33:50 GMT
http://hdl.handle.net/2117/108665
20171011T16:33:50Z
Batlle Arnau, Carles
Delmastro, Diego
Gomis Torné, Joaquin
We construct two possible candidates for nonrelativistic bms(4) algebra in four spacetime dimensions by contracting the original relativistic bms(4) algebra. bms(4) algebra is infinitedimensional and it contains the generators of the Poincare algebra, together with the socalled supertranslations. Similarly, the proposed nrbms(4) algebras can be regarded as two infinitedimensional extensions of the Bargmann algebra. We also study a canonical realization of one of these algebras in terms of the Fourier modes of a free Schrodinger field, mimicking the canonical realization of relativistic bms(4) algebra using a free KleinGordon field.

PMAssisted Synchronous Reluctance Machine flux weakening control for EV and HEV applications
http://hdl.handle.net/2117/108644
PMAssisted Synchronous Reluctance Machine flux weakening control for EV and HEV applications
Trancho, Elena; Ibarra Basabe, Edorta; Arias Pujol, Antoni; Kortabarria, Iñigo; Jurgens, Jonathan; Marengo, Luca; Fricasse, Antonio; Gragger, Johannes
IEEE In this manuscript, a novel robust torque control strategy for Permanent Magnet Assisted Synchronous Reluctance Machine drives applied to electric vehicles and hybrid electric vehicles is presented. Conventional control techniques can highly depend on machine electrical parameters, leading to poor regulation under electrical parameters deviations or, in more serious cases, instabilities. Additionally, machine control can be lost if field weakening is not properly controlled and, as a consequence, uncontrolled regeneration is produced. Thus, advanced control techniques are desirable to guarantee electric vehicle drive controllability in the whole speed/torque operation range and during the whole propulsion system lifetime. In order to achieve these goals, a combination of a robust second order current based Sliding Mode Control and a Look up Table/Voltage Constraint Tracking based hybrid Field Weakening control is proposed, improving the overall control algorithm robustness under parameter deviations. The proposed strategy has been validated experimentally in a full scale automotive test bench (51 kW prototype) for being further implemented in real hybrid and electric vehicles.
Wed, 11 Oct 2017 11:22:46 GMT
http://hdl.handle.net/2117/108644
20171011T11:22:46Z
Trancho, Elena
Ibarra Basabe, Edorta
Arias Pujol, Antoni
Kortabarria, Iñigo
Jurgens, Jonathan
Marengo, Luca
Fricasse, Antonio
Gragger, Johannes
IEEE In this manuscript, a novel robust torque control strategy for Permanent Magnet Assisted Synchronous Reluctance Machine drives applied to electric vehicles and hybrid electric vehicles is presented. Conventional control techniques can highly depend on machine electrical parameters, leading to poor regulation under electrical parameters deviations or, in more serious cases, instabilities. Additionally, machine control can be lost if field weakening is not properly controlled and, as a consequence, uncontrolled regeneration is produced. Thus, advanced control techniques are desirable to guarantee electric vehicle drive controllability in the whole speed/torque operation range and during the whole propulsion system lifetime. In order to achieve these goals, a combination of a robust second order current based Sliding Mode Control and a Look up Table/Voltage Constraint Tracking based hybrid Field Weakening control is proposed, improving the overall control algorithm robustness under parameter deviations. The proposed strategy has been validated experimentally in a full scale automotive test bench (51 kW prototype) for being further implemented in real hybrid and electric vehicles.

Distributed parameter modelbased control of water activity and concentration of reactants in a polymer electrolyte membrane fuel cell
http://hdl.handle.net/2117/108307
Distributed parameter modelbased control of water activity and concentration of reactants in a polymer electrolyte membrane fuel cell
Sarmiento Carnevali, Maria Laura; Serra, Maria; Batlle Arnau, Carles
Water management is still a key challenge for optimal performance and durability of polymer electrolyte membrane (PEM) fuel cells. Water levels along the channel in a PEM fuel cell present important spatial variations that should be taken into account to avoid both local flooding and local drying. In this work, a decentralised model predictive control scheme is designed to maintain the water activity on both anode and cathode sides of the PEM at appropriate levels. The proposed strategy tackles the accumulation of liquid water on the surface of the catalyst layers, and the possibility of local drying, by controlling observed water activity spatial profiles. Classic PEM fuel cell issues like reactant starvation are also considered. High control performance is achieved. The strategy is applied to a validated distributed parameter PEM fuel cell model. Results show increased cell power density in comparison to nonspatial control strategies.
Wed, 04 Oct 2017 07:14:03 GMT
http://hdl.handle.net/2117/108307
20171004T07:14:03Z
Sarmiento Carnevali, Maria Laura
Serra, Maria
Batlle Arnau, Carles
Water management is still a key challenge for optimal performance and durability of polymer electrolyte membrane (PEM) fuel cells. Water levels along the channel in a PEM fuel cell present important spatial variations that should be taken into account to avoid both local flooding and local drying. In this work, a decentralised model predictive control scheme is designed to maintain the water activity on both anode and cathode sides of the PEM at appropriate levels. The proposed strategy tackles the accumulation of liquid water on the surface of the catalyst layers, and the possibility of local drying, by controlling observed water activity spatial profiles. Classic PEM fuel cell issues like reactant starvation are also considered. High control performance is achieved. The strategy is applied to a validated distributed parameter PEM fuel cell model. Results show increased cell power density in comparison to nonspatial control strategies.

Energy management strategy for fuel cellsupercapacitor hybrid vehicles based on prediction of energy demand
http://hdl.handle.net/2117/107433
Energy management strategy for fuel cellsupercapacitor hybrid vehicles based on prediction of energy demand
Carignano, Mauro; Costa Castelló, Ramon; Roda Serrat, Vicente; Nigro, Norberto; Junco, Sergio; Feroldi, Diego Hernan
Offering high efficiency and producing zero emissions Fuel Cells (FCs) represent an excellent alternative to internal combustion engines for powering vehicles to alleviate the growing pollution in urban environments. Due to inherent limitations of FCs which lead to slow transient response, FCbased vehicles incorporate an energy storage system to cover the fast power variations. This paper considers a FC/supercapacitor platform that configures a hard constrained powertrain providing an adverse scenario for the energy management strategy (EMS) in terms of fuel economy and drivability. Focusing on palliating this problem, this paper presents a novel EMS based on the estimation of shortterm future energy demand and aiming at maintaining the state of energy of the supercapacitor between two limits, which are computed online. Such limits are designed to prevent active constraint situations of both FC and supercapacitor, avoiding the use of friction brakes and situations of nonpower compliance in a short future horizon. Simulation and experimentation in a case study corresponding to a hybrid electric bus show improvements on hydrogen consumption and power compliance compared to the widely reported Equivalent Consumption Minimization Strategy. Also, the comparison with the optimal strategy via Dynamic Programming shows a room for improvement to the realtime strategies.
Wed, 06 Sep 2017 08:59:56 GMT
http://hdl.handle.net/2117/107433
20170906T08:59:56Z
Carignano, Mauro
Costa Castelló, Ramon
Roda Serrat, Vicente
Nigro, Norberto
Junco, Sergio
Feroldi, Diego Hernan
Offering high efficiency and producing zero emissions Fuel Cells (FCs) represent an excellent alternative to internal combustion engines for powering vehicles to alleviate the growing pollution in urban environments. Due to inherent limitations of FCs which lead to slow transient response, FCbased vehicles incorporate an energy storage system to cover the fast power variations. This paper considers a FC/supercapacitor platform that configures a hard constrained powertrain providing an adverse scenario for the energy management strategy (EMS) in terms of fuel economy and drivability. Focusing on palliating this problem, this paper presents a novel EMS based on the estimation of shortterm future energy demand and aiming at maintaining the state of energy of the supercapacitor between two limits, which are computed online. Such limits are designed to prevent active constraint situations of both FC and supercapacitor, avoiding the use of friction brakes and situations of nonpower compliance in a short future horizon. Simulation and experimentation in a case study corresponding to a hybrid electric bus show improvements on hydrogen consumption and power compliance compared to the widely reported Equivalent Consumption Minimization Strategy. Also, the comparison with the optimal strategy via Dynamic Programming shows a room for improvement to the realtime strategies.

Observation of the electrochemically active surface area in a proton exchange membrane fuel cell
http://hdl.handle.net/2117/105337
Observation of the electrochemically active surface area in a proton exchange membrane fuel cell
Luna Pacho, Julio Alberto; Usai, Elio; Husar, Attila Peter; Serra, Maria
In this paper a methodology for the estimation of the Electrochemically active Surface Area (ECSA) of a Proton Exchange Membrane Fuel Cell (PEMFC) is developed. Specifically, the ECSA in the Cathode Catalyst Layer (CCL) is estimated, which makes it possible to quantify the amount of active platinum (Pt) in the CCL. In order to estimate the ECSA, the internal conditions of the PEMFC have to be known. A modelbased observer for the distributed parameter dynamics is designed. From the observation of the distributed states, the ECSA can be estimated as well. With the aim of representing the most relevant phenomena that affects the PEMFC voltage, the simulation model includes a twophase water model and the effects of liquid water on the CCL. The results of the methodology are discussed in a simulation environment using the New European Driving Cycle (NEDC) as a case study.
© 20xx 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.
Mon, 12 Jun 2017 08:55:15 GMT
http://hdl.handle.net/2117/105337
20170612T08:55:15Z
Luna Pacho, Julio Alberto
Usai, Elio
Husar, Attila Peter
Serra, Maria
In this paper a methodology for the estimation of the Electrochemically active Surface Area (ECSA) of a Proton Exchange Membrane Fuel Cell (PEMFC) is developed. Specifically, the ECSA in the Cathode Catalyst Layer (CCL) is estimated, which makes it possible to quantify the amount of active platinum (Pt) in the CCL. In order to estimate the ECSA, the internal conditions of the PEMFC have to be known. A modelbased observer for the distributed parameter dynamics is designed. From the observation of the distributed states, the ECSA can be estimated as well. With the aim of representing the most relevant phenomena that affects the PEMFC voltage, the simulation model includes a twophase water model and the effects of liquid water on the CCL. The results of the methodology are discussed in a simulation environment using the New European Driving Cycle (NEDC) as a case study.