The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Asuncion P Cucala - One of the best experts on this subject based on the ideXlab platform.
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improving the traffic model to be used in the optimisation of Mass Transit system electrical infrastructure
Energies, 2017Co-Authors: Alvaro J Lopezlopez, Ramon Rodriguez Pecharroman, Antonio Fernandezcardador, Asuncion P CucalaAbstract:Among the different approaches for minimising the energy consumption of Mass Transit systems (MTSs), a common concern for MTS operators is the improvement of the electrical infrastructure. The traffic on the lines under analysis is one of the most important inputs to the studies devoted to improving MTS infrastructure, since it represents where and how frequently it is possible to save energy. However, on the one hand, MTS electrical studies usually simplify the traffic model, which may lead to a misrepresentation of the energy interactions between trains. On the other hand, if the stochastic traffic is rigorously modelled, the size of the simulation problem could grow excessively, which in turn could make the time to obtain results unmanageable. To cope with this issue, this paper presents a method to obtain a reduced-size set of representative scenarios. Firstly, a traffic model including the most representative stochastic traffic variables is developed. Secondly, a function highly correlated with energy savings is proposed to make it possible to properly characterise the traffic scenarios. Finally, this function is used to select the most representative scenarios. The representative scenario set obtained by the application of this method is shown to be sufficiently accurate with a limited number of scenarios. The traffic approach in this paper improves the accuracy with respect to the usual traffic approach used in the literature.
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smart traffic scenario compressor for the efficient electrical simulation of Mass Transit systems
International Journal of Electrical Power & Energy Systems, 2017Co-Authors: Alvaro J Lopezlopez, Ramon Rodriguez Pecharroman, Antonio Fernandezcardador, Asuncion P CucalaAbstract:Abstract The electrical infrastructure of DC-electrified Mass Transit systems (MTSs) is currently under review. The improvement of MTS infrastructure is commonly tackled by means of optimisation studies. These optimisers usually take large times to obtain their solutions, mainly due to the traffic scenarios that must be taken into account. The optimisation time may be reduced by increasing the sampling time used to obtain the traffic scenarios. However, due to the fast acceleration and braking cycles in MTSs, it is not clear to which extent the sampling time may be increased. In the majority of cases, this parameter is simply set to 1 s. To tackle this concern, this paper presents a compression algorithm which makes it possible to thoroughly reduce the number of snapshots to be included in a given traffic scenario with good energy-saving accuracy figures. The traffic-scenario compressor presented is performed in two stages: a first step finds clusters of similar snapshots in the uncompressed traffic scenario; then a second stage searches for a specific set of trains’ positions and powers that may be directly included in the traffic model used in the optimisation study. The results obtained have shown that the compressor makes it possible to obtain an 80% optimisation-time reduction for a given traffic scenario with a total energy-saving error lower than 5%.
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Assessment of energy-saving techniques in direct-current-electrified Mass Transit systems
Transportation Research Part C: Emerging Technologies, 2014Co-Authors: Álvaro J. López-lópez, Ramon Rodriguez Pecharroman, Antonio Fernández-cardador, Asuncion P CucalaAbstract:Abstract Railway rapid Transit systems are key stones for the sustainability of Mass Transit in developed countries. The overwhelming majority of these railway systems are direct-current (DC) electrified and several energy-saving techniques have been proposed in the literature for these systems. The use of regenerative-braking in trains is generally recognised as the main tool to improve the efficiency of DC-electrified Mass Transit railway systems but the energy recovered in braking cannot always be handled efficiently, above all in low traffic-density situations. Several emerging technologies as energy storage systems or reversible traction substations have the potential for making it possible to efficiently use train-braking. However, a systematic evaluation of their effect is missing in the literature. In this paper, a deep, rigorous and comprehensive study on the factors which affect energy issues in a DC-electrified Mass Transit railway system is carried out. This study clarifies what the actual potential is for energy saving in each situation. Then, a methodology to asses several energy-saving techniques to improve energy efficiency in DC-electrified Mass Transit systems is presented, constituting the main contribution of this paper. This methodology has been conceived to help operators in assessing the effect of railway-infrastructure emerging technologies in Transit systems, so making it possible to shape planning, capacity, etc. It is stepped out in three basic movements. First of all, a traffic-density scan analysis is conducted in order to clarify the effect of the headway on system behaviour. Secondly, several traffic-density scenarios are simulated for a set of infrastructure-expanded cases. Finally, annual energy saving is evaluated by applying a realistic operation timetable. This methodology has been applied to a case study in Madrid Metro (Spain) to illustrate the steps of its application and the effect of several energy-saving techniques on this specific system. Results confirm that regenerative braking generally leads to an important increase of system energy efficiency – especially at high traffic-density scenarios. It has also been proved that infrastructure improvements can also contribute to energy savings and their contributions are more significant at low traffic densities. Annual energy results have been obtained, which may lead to investment decisions by carrying out an appropriate economic assessment based on cost analysis. The main results of the study presented here are likely to apply to other electric traction systems, at least qualitatively.
Haibin Ning - One of the best experts on this subject based on the ideXlab platform.
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design and development of thermoplastic composite roof door for Mass Transit bus
Materials & Design, 2009Co-Authors: Haibin Ning, Selvum Pillay, U K VaidyaAbstract:Abstract Light weight composites possess high specific strength and modulus and have been widely used in various applications such as transportation, marine, and aerospace. Replacing metallic components with reinforced composites in Mass Transit helps to lower weight and therefore increase fuel efficiency and decrease maintenance cost without compromising performance. In this work, an air conditioning cover roof door on a Mass Transit bus was designed, analyzed, and manufactured for a ‘form-fit-function’ replacement of an aluminum component. Novel design using thermoplastic composites materials and thermoforming processing technology were demonstrated to form the part. Innovative composite materials namely thermoplastic polyolefin (TPO) as the outer skin and a ribbed lofted glass mat thermoplastic (GMT) inner liner to provide structural stiffness and strength were used. Weight savings of 39% and reduction of free-standing deflection of 42% were realized using the composite approach compared to the metallic counterpart.
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Process simulation, design and manufacturing of a long fiber thermoplastic composite for Mass Transit application
Composites Part A-applied Science and Manufacturing, 2008Co-Authors: K. Balaji Thattaiparthasarathy, Haibin Ning, Selvum Pillay, Uday K VaidyaAbstract:Abstract Long fiber thermoplastics (LFTs) have witnessed rapid growth in thermoplastics matrix composites, mainly due to developments in the automotive and transportation sector. In LFTs, pelletized thermoplastic polymer matrix is reinforced with long glass or carbon fibers (3–25 mm) are processed by extrusion-compression molding. The current work focuses on the applied science and manufacturing of E-glass/polypropylene (E-glass/PP) LFT composite material. Process simulation was conducted to evaluate the flow of fiber filled viscous charge during the compression molding of the LFT composite. Studies on optimum charge size and placement in the tool, press force, temperature of mold, shrinkage and warpage were also conducted. The flow pattern of the molten charge in the mold and the resulting fiber orientation predicted by process simulation are verified experimentally. The studies have been applied for a Mass Transit/transportation component namely, a LFT battery box access door for form-fit-function to replace a heavy metal door. Weight reduction of 60% was achieved using 40% weight percent E-glass/PP LFT over the metal design.
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design manufacture and analysis of a thermoplastic composite frame structure for Mass Transit
Composite Structures, 2007Co-Authors: Haibin Ning, Gregg M Janowski, U K Vaidya, George HusmanAbstract:Thin-walled composite sub-elements possess excellent properties, including high specific strength, lightweight, internal torque and moment resistance which offer opportunities for applications in Mass Transit and ground transportation. In the present work, an open section thin-walled thermoplastic composite frame segment (sub-element) of a Mass Transit bus was designed, analyzed and manufactured to replace a conventional metal-based design. Three cross-section configurations, rectangular, V-shape and rounded C-shape, were considered, and different lamina stacking sequences, (0/90)6, [±45/(0/90)2]s, and [±45/(0/90)]3 were compared. Carbon fiber/polyphenylene sulphide (carbon/PPS) was the material choice, and single diaphragm forming (SDF) process was adopted to manufacture the frame segment. In-plane compression testing was conducted on the manufactured carbon/PPS composite frame to validate the finite element analysis results. A successful design concept to manufacture strategy of the open thin-walled carbon/PPS thermoplastic composite frame segment was demonstrated. � 2006 Elsevier Ltd. All rights reserved.
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thermoplastic sandwich structure design and manufacturing for the body panel of Mass Transit vehicle
Composite Structures, 2007Co-Authors: Haibin Ning, Uday K Vaidya, Gregg M Janowski, George HusmanAbstract:Abstract Weight savings in vehicles enhances fuel efficiency and decreases maintenance costs, especially in Mass Transit systems. Lightweight composite materials, such as glass fiber reinforced polymers, have been used to replace traditional steel and aluminum components. In this paper, a Mass Transit bus side body panel was designed, analyzed, and manufactured using thermoplastic composite materials. The design featured a sandwich composite with E-glass fiber/polypropylene (glass/PP) face sheets and PP honeycomb core as constituents that provide low weight, high strength and energy absorption benefits. The panel was designed and analyzed using Pro/Engineer 2001 (Pro/E), Altair ® Hypermesh ® 6.0 (Hypermesh) and ANSYS 7.0 (ANSYS). A single diaphragm forming process was used to manufacture the glass/PP face sheets. This process provides excellent consolidation, which was confirmed by microstructural analysis of the face sheets. The face sheets and core material were adhesively bonded and tested to validate the model. The failure of the body panel occurred by adhesive failure when the load reached 11.7 kN. The static loading requirements of the American Public Transportation Association (APTA) for the body panel were met. The thermoplastic composite body panel exhibited excellent weight saving of more than 55% compared to a conventional bus with aluminum skin and supporting steel bars.
George Husman - One of the best experts on this subject based on the ideXlab platform.
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design manufacture and analysis of a thermoplastic composite frame structure for Mass Transit
Composite Structures, 2007Co-Authors: Haibin Ning, Gregg M Janowski, U K Vaidya, George HusmanAbstract:Thin-walled composite sub-elements possess excellent properties, including high specific strength, lightweight, internal torque and moment resistance which offer opportunities for applications in Mass Transit and ground transportation. In the present work, an open section thin-walled thermoplastic composite frame segment (sub-element) of a Mass Transit bus was designed, analyzed and manufactured to replace a conventional metal-based design. Three cross-section configurations, rectangular, V-shape and rounded C-shape, were considered, and different lamina stacking sequences, (0/90)6, [±45/(0/90)2]s, and [±45/(0/90)]3 were compared. Carbon fiber/polyphenylene sulphide (carbon/PPS) was the material choice, and single diaphragm forming (SDF) process was adopted to manufacture the frame segment. In-plane compression testing was conducted on the manufactured carbon/PPS composite frame to validate the finite element analysis results. A successful design concept to manufacture strategy of the open thin-walled carbon/PPS thermoplastic composite frame segment was demonstrated. � 2006 Elsevier Ltd. All rights reserved.
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thermoplastic sandwich structure design and manufacturing for the body panel of Mass Transit vehicle
Composite Structures, 2007Co-Authors: Haibin Ning, Uday K Vaidya, Gregg M Janowski, George HusmanAbstract:Abstract Weight savings in vehicles enhances fuel efficiency and decreases maintenance costs, especially in Mass Transit systems. Lightweight composite materials, such as glass fiber reinforced polymers, have been used to replace traditional steel and aluminum components. In this paper, a Mass Transit bus side body panel was designed, analyzed, and manufactured using thermoplastic composite materials. The design featured a sandwich composite with E-glass fiber/polypropylene (glass/PP) face sheets and PP honeycomb core as constituents that provide low weight, high strength and energy absorption benefits. The panel was designed and analyzed using Pro/Engineer 2001 (Pro/E), Altair ® Hypermesh ® 6.0 (Hypermesh) and ANSYS 7.0 (ANSYS). A single diaphragm forming process was used to manufacture the glass/PP face sheets. This process provides excellent consolidation, which was confirmed by microstructural analysis of the face sheets. The face sheets and core material were adhesively bonded and tested to validate the model. The failure of the body panel occurred by adhesive failure when the load reached 11.7 kN. The static loading requirements of the American Public Transportation Association (APTA) for the body panel were met. The thermoplastic composite body panel exhibited excellent weight saving of more than 55% compared to a conventional bus with aluminum skin and supporting steel bars.
P Ernst - One of the best experts on this subject based on the ideXlab platform.
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stray current control in dc Mass Transit systems
IEEE Transactions on Vehicular Technology, 2005Co-Authors: I Cotton, Charalambos A Charalambous, P Aylott, P ErnstAbstract:Stray current control is essential in direct current (DC) Mass Transit systems where the rail insulation is not of sufficient quality to prevent a corrosion risk to the rails, supporting and third-party infrastructure. This paper details the principles behind the need for stray current control and examines the relationship between the stray current collection system design and its efficiency. The use of floating return rails is shown to provide a reduction in stray current level in comparison to a grounded system, significantly reducing the corrosion level of the traction system running rails. An increase in conductivity of the stray current collection system or a reduction in the soil resistivity surrounding the traction system is shown to decrease the corrosion risk to the supporting and third party infrastructure.
Ramon Rodriguez Pecharroman - One of the best experts on this subject based on the ideXlab platform.
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improving the traffic model to be used in the optimisation of Mass Transit system electrical infrastructure
Energies, 2017Co-Authors: Alvaro J Lopezlopez, Ramon Rodriguez Pecharroman, Antonio Fernandezcardador, Asuncion P CucalaAbstract:Among the different approaches for minimising the energy consumption of Mass Transit systems (MTSs), a common concern for MTS operators is the improvement of the electrical infrastructure. The traffic on the lines under analysis is one of the most important inputs to the studies devoted to improving MTS infrastructure, since it represents where and how frequently it is possible to save energy. However, on the one hand, MTS electrical studies usually simplify the traffic model, which may lead to a misrepresentation of the energy interactions between trains. On the other hand, if the stochastic traffic is rigorously modelled, the size of the simulation problem could grow excessively, which in turn could make the time to obtain results unmanageable. To cope with this issue, this paper presents a method to obtain a reduced-size set of representative scenarios. Firstly, a traffic model including the most representative stochastic traffic variables is developed. Secondly, a function highly correlated with energy savings is proposed to make it possible to properly characterise the traffic scenarios. Finally, this function is used to select the most representative scenarios. The representative scenario set obtained by the application of this method is shown to be sufficiently accurate with a limited number of scenarios. The traffic approach in this paper improves the accuracy with respect to the usual traffic approach used in the literature.
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smart traffic scenario compressor for the efficient electrical simulation of Mass Transit systems
International Journal of Electrical Power & Energy Systems, 2017Co-Authors: Alvaro J Lopezlopez, Ramon Rodriguez Pecharroman, Antonio Fernandezcardador, Asuncion P CucalaAbstract:Abstract The electrical infrastructure of DC-electrified Mass Transit systems (MTSs) is currently under review. The improvement of MTS infrastructure is commonly tackled by means of optimisation studies. These optimisers usually take large times to obtain their solutions, mainly due to the traffic scenarios that must be taken into account. The optimisation time may be reduced by increasing the sampling time used to obtain the traffic scenarios. However, due to the fast acceleration and braking cycles in MTSs, it is not clear to which extent the sampling time may be increased. In the majority of cases, this parameter is simply set to 1 s. To tackle this concern, this paper presents a compression algorithm which makes it possible to thoroughly reduce the number of snapshots to be included in a given traffic scenario with good energy-saving accuracy figures. The traffic-scenario compressor presented is performed in two stages: a first step finds clusters of similar snapshots in the uncompressed traffic scenario; then a second stage searches for a specific set of trains’ positions and powers that may be directly included in the traffic model used in the optimisation study. The results obtained have shown that the compressor makes it possible to obtain an 80% optimisation-time reduction for a given traffic scenario with a total energy-saving error lower than 5%.
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Assessment of energy-saving techniques in direct-current-electrified Mass Transit systems
Transportation Research Part C: Emerging Technologies, 2014Co-Authors: Álvaro J. López-lópez, Ramon Rodriguez Pecharroman, Antonio Fernández-cardador, Asuncion P CucalaAbstract:Abstract Railway rapid Transit systems are key stones for the sustainability of Mass Transit in developed countries. The overwhelming majority of these railway systems are direct-current (DC) electrified and several energy-saving techniques have been proposed in the literature for these systems. The use of regenerative-braking in trains is generally recognised as the main tool to improve the efficiency of DC-electrified Mass Transit railway systems but the energy recovered in braking cannot always be handled efficiently, above all in low traffic-density situations. Several emerging technologies as energy storage systems or reversible traction substations have the potential for making it possible to efficiently use train-braking. However, a systematic evaluation of their effect is missing in the literature. In this paper, a deep, rigorous and comprehensive study on the factors which affect energy issues in a DC-electrified Mass Transit railway system is carried out. This study clarifies what the actual potential is for energy saving in each situation. Then, a methodology to asses several energy-saving techniques to improve energy efficiency in DC-electrified Mass Transit systems is presented, constituting the main contribution of this paper. This methodology has been conceived to help operators in assessing the effect of railway-infrastructure emerging technologies in Transit systems, so making it possible to shape planning, capacity, etc. It is stepped out in three basic movements. First of all, a traffic-density scan analysis is conducted in order to clarify the effect of the headway on system behaviour. Secondly, several traffic-density scenarios are simulated for a set of infrastructure-expanded cases. Finally, annual energy saving is evaluated by applying a realistic operation timetable. This methodology has been applied to a case study in Madrid Metro (Spain) to illustrate the steps of its application and the effect of several energy-saving techniques on this specific system. Results confirm that regenerative braking generally leads to an important increase of system energy efficiency – especially at high traffic-density scenarios. It has also been proved that infrastructure improvements can also contribute to energy savings and their contributions are more significant at low traffic densities. Annual energy results have been obtained, which may lead to investment decisions by carrying out an appropriate economic assessment based on cost analysis. The main results of the study presented here are likely to apply to other electric traction systems, at least qualitatively.
