The Experts below are selected from a list of 3897 Experts worldwide ranked by ideXlab platform
Jorge Ambrósio - One of the best experts on this subject based on the ideXlab platform.
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optimization of high speed railway Pantographs for improving Pantograph catenary contact
Theoretical and Applied Mechanics Letters, 2013Co-Authors: Jorge Ambrósio, Joao Pombo, M F C PereiraAbstract:A crucial system for the operation of high-speed trains is the Pantograph catenary interface as it is the sole responsible to deliver electrical power to the train. Being the catenary a stationary system with a long lifespan it is also less likely to be redesigned and upgraded than the Pantographs that fit the train vehicles. This letter proposes an optimization procedure for the improvement of the contact quality between the Pantograph and the catenary solely based on the redesign of the Pantograph head suspension characteristics. A Pantograph model is defined and validated against experimental dynamic characteristics of existing Pantographs. An optimization strategy based on the use of a global optimization method, to find the vicinity of the optimal solution, followed by the use of a deterministic optimization algorithm, to fine tune the optimal solution, is applied here. The spring stiffness, damping characteristics and bow mass are the design variables used for the Pantograph optimization. The objective of the optimal problem is the minimization of the standard deviation of the contact force history, which is the most important quantity to define the contact quality. The Pantograph head suspension characteristics are allowed to vary within technological realistic limits. It is found that current high-speed railway Pantographs have a limited potential for mechanical improvements, not exceeding 10%–15% on the decrease of the standard deviation of the contact force.
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Environmental and track perturbations on multiple Pantograph interaction with catenaries in high-speed trains
Computers & Structures, 2013Co-Authors: Joao Pombo, Jorge AmbrósioAbstract:The top velocity of high-speed trains is generally limited by the ability to supply the proper amount of energy through the Pantograph-catenary interface. The deterioration of this interaction can lead to the loss of contact, which interrupts the energy supply and originates arcing between the Pantograph and the catenary, or to excessive contact forces that promote wear between the contacting elements. Another important issue is assessing on how the front Pantograph influences the dynamic performance of the rear one in trainsets with two Pantographs. In this work, the track and environmental conditions influence on the Pantograph-catenary is addressed, with particular emphasis in the multiple Pantograph operations. These studies are performed for high speed trains running at 300km/h with relation to the separation between Pantographs. Such studies contribute to identify the service conditions and the external factors influencing the contact quality on the overhead system.
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a computational procedure for the dynamic analysis of the catenary Pantograph interaction in high speed trains
Journal of Theoretical and Applied Mechanics, 2012Co-Authors: Jorge Ambrósio, Joao Pombo, M F C Pereira, Pedro Antunes, Antonio MoscaAbstract:The quality of the current collection of high-speed trains is dependent on the compatibility of the catenary and Pantograph dynamics and on its implications on the contact force. The design and analysis of these systems using proper computational procedures allows capturing all the relevant features of their dynamic behavior. This work proposes an approach to the dynamics of the energy collection system based on the finite elements method, for the catenary, and on multibody dynamics methods, for the Pantograph, integrated via a co-simulation procedure. A contact model based on a penalty formulation is selected to represent the Pantograph-catenary interaction. The methodology is applied to the study of high speed train operations with multiple Pantographs, as this environment constitutes one of the limiting scenarios for the increase of the operation speed.
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Influence of Pantograph suspension characteristics on the contact quality with the catenary for high speed trains
Computers & Structures, 2012Co-Authors: Joao Pombo, Jorge AmbrósioAbstract:In general the electrical energy is provided to the trainsets by the Pantograph-catenary contact. The study of this system contributes to decrease the number of incidents and the maintenance and interoperability costs. Here a finite element method and a multibody dynamics approach are used to handle the catenary and the Pantograph dynamics, implemented in a validated computational tool. The objective is to understand how Pantograph parameters influence contact force characteristics and catenary uplift. The results provide indications on how the Pantographs can be modified, in a design environment, or tuned to improve the performance of the overhead contact system.
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Influence of the Aerodynamic Forces on the Pantograph-Catenary System for High Speed Trains
Vehicle System Dynamics, 2009Co-Authors: Joao Pombo, Jorge Ambrósio, Manuel Francisco Pereira, Frederico Rauter, Andrea Collina, Alan FacchinettiAbstract:Most of the high-speed trains in operation today have the electrical power supply delivered through the Pantograph-catenary system. The understanding of the dynamics of this system is fundamental since it contributes to decrease the number of incidents related to these components, to reduce the maintenance and to improve interoperability. From the mechanical point of view, the most important feature of the Pantograph-catenary system consists in the quality of the contact between the contact wire of the catenary and the contact strips of the Pantograph. The catenary is represented by a finite element model, whereas the Pantograph is described by a detailed multibody model, analysed through two independent codes in a co-simulation environment. A computational procedure ensuring the efficient communication between the multibody and finite element codes, through shared computer memory, and suitable contact force models were developed. The models presented here are contributions for the identification of the dynamic behaviour of the Pantograph and of the interaction phenomena in the Pantograph-catenary system of high-speed trains due to the action of aerodynamics forces. The wind forces are applied on the catenary by distributing them on the finite element mesh. Since the multibody formulation does not include explicitly the geometric information of the bodies, the wind field forces are applied to each body of the Pantograph as time-dependent nonlinear external forces. These wind forces can be characterised either by using computational fluid dynamics or experimental testing in a wind tunnel. The proposed methodologies are demonstrated by the application to real operation scenarios for high-speed trains, with the purpose of defining service limitations based on train and wind speed combination.
Joao Pombo - One of the best experts on this subject based on the ideXlab platform.
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optimization of high speed railway Pantographs for improving Pantograph catenary contact
Theoretical and Applied Mechanics Letters, 2013Co-Authors: Jorge Ambrósio, Joao Pombo, M F C PereiraAbstract:A crucial system for the operation of high-speed trains is the Pantograph catenary interface as it is the sole responsible to deliver electrical power to the train. Being the catenary a stationary system with a long lifespan it is also less likely to be redesigned and upgraded than the Pantographs that fit the train vehicles. This letter proposes an optimization procedure for the improvement of the contact quality between the Pantograph and the catenary solely based on the redesign of the Pantograph head suspension characteristics. A Pantograph model is defined and validated against experimental dynamic characteristics of existing Pantographs. An optimization strategy based on the use of a global optimization method, to find the vicinity of the optimal solution, followed by the use of a deterministic optimization algorithm, to fine tune the optimal solution, is applied here. The spring stiffness, damping characteristics and bow mass are the design variables used for the Pantograph optimization. The objective of the optimal problem is the minimization of the standard deviation of the contact force history, which is the most important quantity to define the contact quality. The Pantograph head suspension characteristics are allowed to vary within technological realistic limits. It is found that current high-speed railway Pantographs have a limited potential for mechanical improvements, not exceeding 10%–15% on the decrease of the standard deviation of the contact force.
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Environmental and track perturbations on multiple Pantograph interaction with catenaries in high-speed trains
Computers & Structures, 2013Co-Authors: Joao Pombo, Jorge AmbrósioAbstract:The top velocity of high-speed trains is generally limited by the ability to supply the proper amount of energy through the Pantograph-catenary interface. The deterioration of this interaction can lead to the loss of contact, which interrupts the energy supply and originates arcing between the Pantograph and the catenary, or to excessive contact forces that promote wear between the contacting elements. Another important issue is assessing on how the front Pantograph influences the dynamic performance of the rear one in trainsets with two Pantographs. In this work, the track and environmental conditions influence on the Pantograph-catenary is addressed, with particular emphasis in the multiple Pantograph operations. These studies are performed for high speed trains running at 300km/h with relation to the separation between Pantographs. Such studies contribute to identify the service conditions and the external factors influencing the contact quality on the overhead system.
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a computational procedure for the dynamic analysis of the catenary Pantograph interaction in high speed trains
Journal of Theoretical and Applied Mechanics, 2012Co-Authors: Jorge Ambrósio, Joao Pombo, M F C Pereira, Pedro Antunes, Antonio MoscaAbstract:The quality of the current collection of high-speed trains is dependent on the compatibility of the catenary and Pantograph dynamics and on its implications on the contact force. The design and analysis of these systems using proper computational procedures allows capturing all the relevant features of their dynamic behavior. This work proposes an approach to the dynamics of the energy collection system based on the finite elements method, for the catenary, and on multibody dynamics methods, for the Pantograph, integrated via a co-simulation procedure. A contact model based on a penalty formulation is selected to represent the Pantograph-catenary interaction. The methodology is applied to the study of high speed train operations with multiple Pantographs, as this environment constitutes one of the limiting scenarios for the increase of the operation speed.
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Influence of Pantograph suspension characteristics on the contact quality with the catenary for high speed trains
Computers & Structures, 2012Co-Authors: Joao Pombo, Jorge AmbrósioAbstract:In general the electrical energy is provided to the trainsets by the Pantograph-catenary contact. The study of this system contributes to decrease the number of incidents and the maintenance and interoperability costs. Here a finite element method and a multibody dynamics approach are used to handle the catenary and the Pantograph dynamics, implemented in a validated computational tool. The objective is to understand how Pantograph parameters influence contact force characteristics and catenary uplift. The results provide indications on how the Pantographs can be modified, in a design environment, or tuned to improve the performance of the overhead contact system.
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Influence of the Aerodynamic Forces on the Pantograph-Catenary System for High Speed Trains
Vehicle System Dynamics, 2009Co-Authors: Joao Pombo, Jorge Ambrósio, Manuel Francisco Pereira, Frederico Rauter, Andrea Collina, Alan FacchinettiAbstract:Most of the high-speed trains in operation today have the electrical power supply delivered through the Pantograph-catenary system. The understanding of the dynamics of this system is fundamental since it contributes to decrease the number of incidents related to these components, to reduce the maintenance and to improve interoperability. From the mechanical point of view, the most important feature of the Pantograph-catenary system consists in the quality of the contact between the contact wire of the catenary and the contact strips of the Pantograph. The catenary is represented by a finite element model, whereas the Pantograph is described by a detailed multibody model, analysed through two independent codes in a co-simulation environment. A computational procedure ensuring the efficient communication between the multibody and finite element codes, through shared computer memory, and suitable contact force models were developed. The models presented here are contributions for the identification of the dynamic behaviour of the Pantograph and of the interaction phenomena in the Pantograph-catenary system of high-speed trains due to the action of aerodynamics forces. The wind forces are applied on the catenary by distributing them on the finite element mesh. Since the multibody formulation does not include explicitly the geometric information of the bodies, the wind field forces are applied to each body of the Pantograph as time-dependent nonlinear external forces. These wind forces can be characterised either by using computational fluid dynamics or experimental testing in a wind tunnel. The proposed methodologies are demonstrated by the application to real operation scenarios for high-speed trains, with the purpose of defining service limitations based on train and wind speed combination.
Erhan Akın - One of the best experts on this subject based on the ideXlab platform.
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a new experimental approach using image processing based tracking for an efficient fault diagnosis in Pantograph catenary systems
IEEE Transactions on Industrial Informatics, 2017Co-Authors: Ebru Karaköse, İlhan Aydin, Mehmet Karaköse, Muhsin Tunay Gencoglu, Erhan AkınAbstract:The periodical maintenance of railway systems is very important in terms of maintaining safe and comfortable transportation. In particular, the monitoring and diagnosis of faults in the Pantograph catenary system are required to provide a transmission from the catenary line to the electric energy locomotive. Surface wear that is caused by the interaction between the Pantograph and catenary and nonuniform distribution on the surface of a Pantograph of the contact points can cause serious accidents. In this paper, a novel approach is proposed for image processing-based monitoring and fault diagnosis in terms of the interaction and contact points between the Pantograph and catenary in a moving train. For this purpose, the proposed method consists of two stages. In the first stage, the Pantograph catenary interaction has been modeled; the simulation results were given a failure analysis with a variety of scenarios. In the second stage, the contact points between the Pantograph and catenary were detected and implemented in real time with image processing algorithms using actual video images. The Pantograph surface for a fault analysis was divided into three regions: safe, dangerous, and fault. The fault analysis of the system was presented using the number of contact points in each region. The experimental results demonstrate the effectiveness, applicability, and performance of the proposed approach.
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anomaly detection using a modified kernel based tracking in the Pantograph catenary system
Expert Systems With Applications, 2015Co-Authors: İlhan Aydin, Mehmet Karaköse, Erhan AkınAbstract:A new contactless condition monitoring method is proposed for anomaly detection in the Pantograph-catenary system.Kernel-based tracking is modified for a robust tracking of catenary wire.The foreground detection and object tracking are combined for simultaneously arcing detection.The detailed analysis of the trajectory of the contact wire gives useful information to evaluate the Pantograph condition. Condition monitoring is very important in railway systems to reduce maintenance costs and to increase the safety. A high power is needed for the movement of the electric train and collection of the current is critical. Faults occurred in the current collection system cause serious damage in the line and disrupt the railway traffic. When a wear occurs on the contact strip, the asymmetries and distortion are generated in supply voltage and current waveforms because of Pantograph arcing. Therefore, the monitoring of Pantograph-catenary system has been a hot topic in recent years. This paper deals with a method based on kernel-based object tracking for identifying the interaction between Pantograph-catenary systems that gives useful information about the problems of catenary-Pantograph systems. The method consists of two key components. The first component is based on the kernel based tracking of the contact wire. The contact point between Pantograph and catenary is tracked and the obtained positions are saved as a signal. In the other hand, the foreground of each frame is found by using Gaussian mixture models (GMMs). The occurred arcs are detected by combining tracking and foreground detection methods. The second component employs S-transform for analyzing the Pantograph problems, which are used to detect the faults occurred on Pantograph strip. The experimental results imply that the proposed method is useful to detect burst of arcing, and irregular positioning of the contact wire.
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a robust anomaly detection in Pantograph catenary system based on mean shift tracking and foreground detection
Systems Man and Cybernetics, 2013Co-Authors: İlhan Aydin, Mehmet Karaköse, Erhan AkınAbstract:This study presents a robust condition monitoring and anomaly detection for Pantograph-catenary system. The Pantograph overhead system is monitored by using a digital camera. A general framework for anomaly detection for Pantograph-catenary system consists of two key components. The first component is based on mean-shift tracking of contact wire. Therefore, the contact point between Pantograph and catenary can be continuously monitored and anomaly contact to some points will be detected. The second component uses Gaussian mixture model (GMM) for foreground detection. When the foreground of the current frame has been detected, the mean-shift tracking and GMM combines trajectory-based and region-based information for detection any anomaly in Pantograph-catenary interaction. The experimental results show that proposed method is useful to detect burst of arcing, and irregular positioning of contact line.
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A new computer vision approach for active Pantograph control
2013 IEEE INISTA, 2013Co-Authors: İlhan Aydin, Ebru Karaköse, Mehmet Karaköse, Tunay M. Gençoğlu, Erhan AkınAbstract:Railway vehicles have become a modern transport media day by day. With the development of high-speed trains, this transportation way has been widely used for the transportation of people and cargo. However, several fault type in the Pantograph-catenary system affects the performance of the train. Contact between a Pantograph and catenary must slide along train movement. A sufficient lifting force should be applied to the contact wire when train moves. Vibrations occurred between a Pantograph and catenary system and oscillations of contact wire cause the loss of contact. So, burst of arcing occurs in contact point. In this study, a new computer vision based method is proposed to control the contact force. The proposed algorithm utilizes the edge detection and Hough transform for detection of Pantograph height. The obtained height is given to the control algorithm and the height of the Pantograph is adjusted. The proposed method is verified by using a video taken from real Pantograph and efficient results has been obtained.
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a new contactless fault diagnosis approach for Pantograph catenary system
Proceedings of 15th International Conference MECHATRONIKA, 2012Co-Authors: İlhan Aydin, Mehmet Karaköse, Erhan AkınAbstract:Railway transport is one of the most important mass transportation media in the worldwide. With the development of trains speed, safety and comfort levels of railways is getting more importance day by day. Besides high level of security requirement, detection of anomaly for rail and road shall be early identified for decreasing operation and maintenance expenditures. The Pantograph-catenary system has an important role for collecting the current in electrical railways. The problem occurred in this system will affect the current collection performance of electrified trains. In this paper, a new image processing based technique is proposed to detect the arcing faults occurred between catenary and Pantograph contact. The proposed method takes one frame from the digital camera and then the edge detection algorithm extracts the edges of Pantograph. The arcing between contact wire and Pantograph is detected by examining the position of contact wire of Pantograph's edge.
Yang Song - One of the best experts on this subject based on the ideXlab platform.
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a spatial coupling model to study dynamic performance of Pantograph catenary with vehicle track excitation
Mechanical Systems and Signal Processing, 2021Co-Authors: Yang Song, Zhigang Liu, Zhiwei Wang, Ruichen WangAbstract:Abstract In the high-speed railway industry, the Pantograph-catenary system is responsible to provide continuous electric energy for the high-speed train. The Pantograph-catenary system suffers multiple impacts from the complex work environment. The vehicle-track excitation is one of the normal disturbances to the Pantograph-catenary interaction. Previous studies only consider the vertical effect of the vehicle-track vibration on the Pantograph-catenary interaction. To address this deficiency, both of the Pantograph-catenary and vehicle-track models are constructed in this paper. The validations of both models are verified by the experimental test and the world benchmark, respectively. The Pantograph base follows the translations and rotations of the car-body caused by random rail irregularities. In combination with a spatial contact model between the contact wire and the Pantograph strip, the spatial vibration of the carbody can be fully considered in the Pantograph-catenary interaction. The statistical analysis, stochastic analysis and frequency analysis are performed to make sense of the effect of the random track irregularities on the Pantograph-catenary interaction. The deviation of the contact point away from the strip centre caused by the carbody vibration is also analysed. The results show that the reliability of the Pantograph-catenary system shows a continuous decrease in the degradation of rail quality. The carbody vibration may cause the de-wirement of the Pantograph in extreme conditions. Finally, an application example is given to evaluate the dynamic performance of the Pantograph-catenary system running on the China high-speed network with realistic rail irregularities.
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Effective Measures to Improve Current Collection Quality for Double Pantographs and Catenary Based on Wave Propagation Analysis
IEEE Transactions on Vehicular Technology, 2020Co-Authors: Yang Song, Zhigang LiuAbstract:The Pantograph installed on the train roof is responsible for collecting the electrical energy via the sliding contact with the catenary constructed along the railroad. To enhance the carrying capacity of the high-speed train, multiple Pantographs are normally mounted on the EMU (Electrical Multiple Unit train) to interact simultaneously with the catenary. Especially in China, the double Pantographs-catenary interaction is gradually becoming the mainstream in the newly built high-speed network. The biggest challenge of double-Pantograph operation is the deterioration of the current collection quality of the trailing Pantograph. The mechanical wave excited by the leading Pantograph propagates along the contact wire and disturbs the trailing Pantograph. This paper attempts to propose effective measures to improve the current collection quality of the trailing Pantograph. To improve the understanding of the wave propagation in the contact wire excited by two Pantographs, the double Pantographs-catenary model is established using a FEM (Finite Element Method) approach. Through the analysis of the contact wire uplift response excited by a single moving force, the optimal interval of double Pantographs is discussed. The results indicate that the bad interval appears at the velocity peak of the contact wire uplift, whereas, the good interval appears at the valley value of the contact wire uplift velocity. Based on this idea, the formula of optimal interval of double Pantographs is proposed, and its validity is verified using the parameters of the European and China high-speed networks. Then the damper is introduced to the steady arm to reduce the wave intensity. The simulation results show that the slight steady arm damping has a positive effect on the performance of the double Pantographs-catenary interaction.
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active control of contact force for high speed railway Pantograph catenary based on multi body Pantograph model
Mechanism and Machine Theory, 2017Co-Authors: Yang Song, Zhigang Liu, Guiming Mei, Huajiang Ouyang, Hongrui WangAbstract:Abstract Active control of Pantograph is a promising approach in improving the current collection quality of high-speed railway Pantograph-catenary system. To address the shortcomings of the lumped-parameter Pantograph model used in previous studies, a multi-body model of Pantograph is established, and two configurations of installing actuators on a multi-body Pantograph are presented. In combination with a nonlinear finite element model of catenary, the control performance is evaluated through several numerical simulations. First of all, the effect of control gains on the control performance is analyzed. Then considering more realistic conditions, the controller time-delay and the limitation of controller sensitivity are included, whose influence on the control performance is investigated. At last, considering realistic external disturbance (strong wind load and locomotive vibration) to Pantograph-catenary system the control performance is evaluated in decreasing the fluctuation in contact force as well as eliminating the contact loss. The results indicate that the proposed controller with larger control gains has better performance in decreasing the fluctuation of the contact force between the multi-body Pantograph and the nonlinear finite element catenary, but has lower robustness against the controller time-delay. The reduction of controller sensitivity results in a fluctuating degradation of the control performance.
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sliding mode control with pd sliding surface for high speed railway Pantograph catenary contact force under strong stochastic wind field
Shock and Vibration, 2017Co-Authors: Yang Song, Hongrui Wang, Huajiang Ouyang, Xiaobing LuAbstract:As is well known, the external disturbance (especially the stochastic wind load) has nonnegligible effect on the operation of Pantograph-catenary system, which may cause the strong fluctuation in contact force as well as the increased occurrence of contact loss. In order to improve the current collection quality of a high-speed railway Pantograph-catenary system under a strong stochastic wind field, a sliding mode controller with a proportional-derivative (PD) sliding surface for a high-speed active Pantograph is proposed. The nonlinear finite element procedure is employed to establish the catenary model. The fluctuating wind speeds along catenary are simulated using empirical spectrums. The buffeting forces exerted on contact and messenger wires are derived to construct the stochastic wind field along the catenary. A PD sliding surface is properly determined to guarantee that the mechanical impedance of Pantograph head at the dominant frequencies of contact force decreases when the sliding surface approaches zero. Through several numerical simulations with different wind velocities and wind angles, the control performance of two popular control laws (proportional switching law and constant switching law) is evaluated.
Zhigang Liu - One of the best experts on this subject based on the ideXlab platform.
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a spatial coupling model to study dynamic performance of Pantograph catenary with vehicle track excitation
Mechanical Systems and Signal Processing, 2021Co-Authors: Yang Song, Zhigang Liu, Zhiwei Wang, Ruichen WangAbstract:Abstract In the high-speed railway industry, the Pantograph-catenary system is responsible to provide continuous electric energy for the high-speed train. The Pantograph-catenary system suffers multiple impacts from the complex work environment. The vehicle-track excitation is one of the normal disturbances to the Pantograph-catenary interaction. Previous studies only consider the vertical effect of the vehicle-track vibration on the Pantograph-catenary interaction. To address this deficiency, both of the Pantograph-catenary and vehicle-track models are constructed in this paper. The validations of both models are verified by the experimental test and the world benchmark, respectively. The Pantograph base follows the translations and rotations of the car-body caused by random rail irregularities. In combination with a spatial contact model between the contact wire and the Pantograph strip, the spatial vibration of the carbody can be fully considered in the Pantograph-catenary interaction. The statistical analysis, stochastic analysis and frequency analysis are performed to make sense of the effect of the random track irregularities on the Pantograph-catenary interaction. The deviation of the contact point away from the strip centre caused by the carbody vibration is also analysed. The results show that the reliability of the Pantograph-catenary system shows a continuous decrease in the degradation of rail quality. The carbody vibration may cause the de-wirement of the Pantograph in extreme conditions. Finally, an application example is given to evaluate the dynamic performance of the Pantograph-catenary system running on the China high-speed network with realistic rail irregularities.
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Effective Measures to Improve Current Collection Quality for Double Pantographs and Catenary Based on Wave Propagation Analysis
IEEE Transactions on Vehicular Technology, 2020Co-Authors: Yang Song, Zhigang LiuAbstract:The Pantograph installed on the train roof is responsible for collecting the electrical energy via the sliding contact with the catenary constructed along the railroad. To enhance the carrying capacity of the high-speed train, multiple Pantographs are normally mounted on the EMU (Electrical Multiple Unit train) to interact simultaneously with the catenary. Especially in China, the double Pantographs-catenary interaction is gradually becoming the mainstream in the newly built high-speed network. The biggest challenge of double-Pantograph operation is the deterioration of the current collection quality of the trailing Pantograph. The mechanical wave excited by the leading Pantograph propagates along the contact wire and disturbs the trailing Pantograph. This paper attempts to propose effective measures to improve the current collection quality of the trailing Pantograph. To improve the understanding of the wave propagation in the contact wire excited by two Pantographs, the double Pantographs-catenary model is established using a FEM (Finite Element Method) approach. Through the analysis of the contact wire uplift response excited by a single moving force, the optimal interval of double Pantographs is discussed. The results indicate that the bad interval appears at the velocity peak of the contact wire uplift, whereas, the good interval appears at the valley value of the contact wire uplift velocity. Based on this idea, the formula of optimal interval of double Pantographs is proposed, and its validity is verified using the parameters of the European and China high-speed networks. Then the damper is introduced to the steady arm to reduce the wave intensity. The simulation results show that the slight steady arm damping has a positive effect on the performance of the double Pantographs-catenary interaction.
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active control of contact force for high speed railway Pantograph catenary based on multi body Pantograph model
Mechanism and Machine Theory, 2017Co-Authors: Yang Song, Zhigang Liu, Guiming Mei, Huajiang Ouyang, Hongrui WangAbstract:Abstract Active control of Pantograph is a promising approach in improving the current collection quality of high-speed railway Pantograph-catenary system. To address the shortcomings of the lumped-parameter Pantograph model used in previous studies, a multi-body model of Pantograph is established, and two configurations of installing actuators on a multi-body Pantograph are presented. In combination with a nonlinear finite element model of catenary, the control performance is evaluated through several numerical simulations. First of all, the effect of control gains on the control performance is analyzed. Then considering more realistic conditions, the controller time-delay and the limitation of controller sensitivity are included, whose influence on the control performance is investigated. At last, considering realistic external disturbance (strong wind load and locomotive vibration) to Pantograph-catenary system the control performance is evaluated in decreasing the fluctuation in contact force as well as eliminating the contact loss. The results indicate that the proposed controller with larger control gains has better performance in decreasing the fluctuation of the contact force between the multi-body Pantograph and the nonlinear finite element catenary, but has lower robustness against the controller time-delay. The reduction of controller sensitivity results in a fluctuating degradation of the control performance.
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an extended habedank s equation based emtp model of Pantograph arcing considering Pantograph catenary interactions and train speeds
IEEE Transactions on Power Delivery, 2016Co-Authors: Ying Wang, Zhigang Liu, Ke Huang, Hongrui Wang, Shibin GaoAbstract:Pantograph arcing is a more and more common and prominent phenomenon in ac-electrified railway systems, especially with the increase of Pantograph-catenary (PAC) interaction and train speed. In order to address this issue, an extended Habedank’s equation-based model, by means of the Electromagnetic Transients Program (EMTP), is presented to obtain equivalent modeling for Pantograph arcing studies considering train speeds in this paper. First, the Pantograph arcing phenomenon is investigated, such as transient mechanisms and influencing factors. Second, based on the features of existing and emerging Pantograph arcing, Habedank’s arc equations are further derived and studied by improving voltage gradient and power dissipation. Next, due to the relationship among voltage gradient, power dissipation, and arc length, the maximum detachment interval law between Pantograph and contact wire is obtained by establishing the finite-element model for PAC interaction, and the ultimate extended Habedank’s equation-based EMTP model of Pantograph arcing considering different train speeds is acquired. Then, the related model parameters are discussed and determined. Finally, based on the China Beijing-Yizhuang HSR line model in EMTP, the arc characteristic differences considering loads under different parameter values are compared and analyzed. The comparison results illustrate that the proposed model can be feasible to determine and reveal the Pantograph arcing characteristics and influences in the HSR system as well as the PAC contact loss problems.
