scholarly journals The Influence of Controller Parameters on the Quality of the Train Converter Current

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
M. Brenna ◽  
F. Foiadelli ◽  
D. Zaninelli
Keyword(s):  
Traffic Control ◽  
High Speed ◽  
Control Structure ◽  
Pi Controller ◽  
Signaling System ◽  
Harmonic Content ◽  
High Speed Trains ◽  
Set Up ◽  
A Current

This paper presents a stability analysis of train converters in order to evaluate how the controller parameters affect the absorbed current. The new dynamic model presented in this paper is capable of considering the time-variant nature of the system for the correct tuning of the feedback proportional-integral PI controller, applying a current controlled modulation technique never used in high-power traction converters. The reduction of the harmonic content of the current absorbed by a converter employed at the input stage onboard high-speed trains is really important, considering the interaction with the signaling system set up for traffic control. A computer model of the converter, considering both the power and the control structure, has also been implemented in order to deliver a validated tool for the developed theoretical analysis.

scholarly journals Effect of the turning characteristics of underfloor wheel lathes on the evolution of wheel polygonisation

2018 ◽  
Vol 233 (5) ◽  
pp. 479-488 ◽  
Author(s):  
Dabin Cui ◽  
Boyang An ◽  
Paul Allen ◽  
Ruichen Wang ◽  
Ping Wang ◽  
...  
Keyword(s):  
Fourth Order ◽  
High Speed ◽  
Higher Order ◽  
Ride Quality ◽  
Sustained Use ◽  
High Speed Trains ◽  
Cut Quality ◽  
Multiple Unit ◽  
Component Failures

During both running and wheel cut operations, wheels of railway vehicles and the friction rollers that support and drive the wheelset on a typical wheel cut lathe are subject to wear and hence are likely to develop out-of-round characteristics after sustained use. The resulting out-of-round wheels can significantly affect the ride quality and can potentially increase the incidence of fatigue-related component failures due to the resulting higher intensity loading cycles. Furthermore, the corresponding out-of-round characteristics of the lathe's friction rollers will continue to degrade the subsequent cut quality of wheels. For the analysis of the out-of-round characteristics caused by an underfloor wheel lathe used for the high-speed trains in China, a mathematical model based on a typical electric multiple unit (EMU) vehicle's wheelsets and their interactions with the wheel lathe friction rollers was established. Factors influencing the cut quality of the wheels, including the number of cuts, eccentricity forms of the friction rollers and the longitudinal spacing of the two rollers, have been analysed. The results show that two cuts can effectively remove the higher order polygon on the wheel surface. The eccentricity and phase angle of the friction rollers have no influence on the cut quality of higher order polygons, whereas they are the primary cause for the fourth-order polygons. The severity of the fourth-order polygon depends on the level and the phase of the eccentricity of the friction rollers. The space of the two rollers can also significantly affect the cut quality. Obtaining the theoretical and practical value for the maintenance of polygonised wheels using the underfloor lathe is the main outcome of this study.

scholarly journals A Fast Hybrid Beamforming Scheme for High-Speed Railway Communications

Electronics ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 998
Author(s):  
Yu Xiao ◽  
Gang Qiu ◽  
Yafeng Wang
Keyword(s):  
High Speed ◽  
Low Complexity ◽  
Spectrum Efficiency ◽  
System Throughput ◽  
Quality Of Services ◽  
Communication Service ◽  
High Speed Railway ◽  
High Speed Trains ◽  
Hybrid Beamforming

With the increasingly demand for reliable mobile communication service in the high-speed railway (HSR) system, the service stability of HSR communication is of great concern in recent research. Focusing on ensuring the quality of services (QoS) and system throughput, massive multi-input multi-output (massive MIMO) and beamforming technologies have been widely applied. In this paper, aiming to minimize the communication outage probability (OP) and not to decrease spectrum efficiency (SE) too much, we propose a fast HBF (F-HBF) scheme for HSR communications. The proposed scheme uses a low-complexity beam-searching algorithm to trace high-speed trains in real time. The simulation results verify that the proposed scheme can significantly reduce OP without too much SE degradation.

Quality of Service on Link Aggregation Network Virtualization for Docker Containers

2019 ◽  
Vol 886 ◽  
pp. 227-232
Author(s):  
Yanapat Chuchuen ◽  
Kritwara Rattanaopas ◽  
Sarapee Chunkaew
Keyword(s):  
Traffic Control ◽  
Load Balance ◽  
High Speed ◽  
Large Scale ◽  
Network Virtualization ◽  
Network Bandwidth ◽  
Working Together ◽  
Multiple Network ◽  
Implementation Tool

Docker engine is an extremely powerful tool for PaaS platform of cloud computing. It gives benefits for large-scale of internet services. Web service is basic service for everyone who requires to access internet that web infrastructure must has scalability with load-balance web server called reverse proxy. The key answers for a large-scale web must have multiple web servers working together with high speed bandwidth. Moreover, multiple clusters can find in the same data center there are required to assign priority and quality of each cluster service. We investigate load-balance assign link aggregation with network QoS by using pipework script and traffic control tool in frontend reverse proxy server on each cluster. Our research evaluates scenario of network QoS ratios which include 50/50, 60/40, 70/30 and 80/20. We compare network bandwidth between both web reverse proxy clusters. The results present our designed and implementation tool not only can control network QoS on each web reverse proxy cluster in all load-balance link aggregation modes which include round-robin, XOR and ALB but also those of clusters can access multiple network interface. In experiment, average network bandwidths in all QoS cases are around 200 MB per second for link aggregation of 2 gigabit interface.

Virtual homologation of high-speed trains in railway tunnels: A new iterative numerical approach for train-tunnel pressure signature

2021 ◽  
pp. 095440972110291
Author(s):  
Elia Brambilla ◽  
Paolo Schito ◽  
Claudio Somaschini ◽  
Daniele Rocchi
Keyword(s):  
High Speed ◽  
Numerical Approach ◽  
Design Tool ◽  
Critical Conditions ◽  
Rolling Stock ◽  
Railway Tunnel ◽  
High Speed Trains ◽  
European Regulations ◽  
Set Up ◽  
Full Scale Tests

Large overpressures can be produced when a high-speed train enters and crosses a railway tunnel. Predicting them is important since, in critical conditions, pressure variations may be dangerous for train structures and for passengers’ health and comfort. European regulations impose pressure thresholds which trains must comply with in order to be homologated for travelling through tunnels. Currently, full-scale tests are required to demonstrate respect of these prescriptions. In this work, a procedure for calculating the pressure variations inside the tunnel based on 3 D steady CFD simulations and a 1 D compressible fluid-dynamics model is proposed, to be used both as a design tool and for virtual homologation of new rolling stock. Results of a large experimental campaign performed on the Italian high-speed line are used to set-up the proposed methodology and to validate it. Different train geometries, tunnel crossing speeds and tunnel initial air conditions are considered.

Study on Evaluation Method of High-Speed Train Based on Bipartite Graph

2013 ◽  
Vol 364 ◽  
pp. 843-848
Author(s):  
Ling Xuan Li ◽  
Yuan Yua Ma ◽  
Zi Liang Liu
Keyword(s):  
Resource Allocation ◽  
Bipartite Graph ◽  
High Speed ◽  
Evaluation Method ◽  
High Speed Train ◽  
Key Factors ◽  
Performance Indices ◽  
High Speed Trains ◽  
High Influence

Based on the resource allocation method of bipartite graph projected to one-mode graph, the bipartite graph network is established using six evaluating comfortableness indices and seven subsystems of high-speed train as the vertices. Our research shows that: This method can be used to find out the key factors which have high influence on the high-speed trains comprehensive comfortableness; also its ratio can be obtained. The overall quality of the high-speed train also can be forecasted by this method if the seven subsystems performance indices are given. Meanwhile, the interacting dependency level among the indices can be obtained.

A Study of Aerodynamic Effects of High-Speed Trains through Tunnels

2011 ◽  
Vol 94-96 ◽  
pp. 1663-1667
Author(s):  
Jing Zhao ◽  
Ren Xian Li
Keyword(s):  
High Speed ◽  
Stokes Equations ◽  
Navier Stokes ◽  
High Speed Train ◽  
Navier Stokes Equations ◽  
Geometry Model ◽  
Flow Geometry ◽  
High Speed Trains ◽  
Set Up ◽  
Numerical Calculation Method

In this paper, the aerodynamic effects of high-speed train passing in tunnels are investigated in numerical calculation method of hydromechanics. According to the actual situation of flow filed when the train through the tunnel, the flow geometry model is set up. The flow problem is described by Navier-Stokes equations of unsteady viscous compressible fluid and k-e two equations turbulent model. Thereby the aerodynamic effects of the train through the tunnel are analyzed comprehensively. The changes of the air pressure in tunnel caused by high-speed train entering into the tunnel are mainly analyzed. In addition, the mechanical characteristics of carriages when two train in the tunnel passing through each other are analyzed.

scholarly journals High-Speed Train Stop-Schedule Optimization Based on Passenger Travel Convenience

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Dingjun Chen ◽  
Shaoquan Ni ◽  
Chang’an Xu ◽  
Hongxia Lv ◽  
Simin Wang
Keyword(s):  
High Speed ◽  
Hybrid Genetic Algorithm ◽  
Economic Benefits ◽  
Operation Planning ◽  
Schedule Optimization ◽  
Passenger Travel ◽  
High Speed Trains ◽  
Specific Manifestation

The stop-schedules for passenger trains are important to the operation planning of high-speed trains, and they decide the quality of passenger service and the transportation efficiency. This paper analyzes the specific manifestation of passenger travel convenience and proposes the concepts of interstation accessibility and degree of accessibility. In consideration of both the economic benefits of railway corporations and the travel convenience of passengers, a multitarget optimization model is established. The model aims at minimizing stop cost and maximizing passenger travel convenience. Several constraints are applied to the model establishment, including the number of stops made by individual trains, the frequency of train service received by each station, the operation section, and the 0-1 variable. A hybrid genetic algorithm is designed to solve the model. Both the model and the algorithm are validated through case study.

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