Reliability Allocation for a System with Complex Redundancy

2013 ◽  
Vol 436 ◽  
pp. 505-510 ◽  
Author(s):  
Zdenek Vintr ◽  
Tomas Vintr
Keyword(s):  
High Speed ◽  
Suggested Method ◽  
Parallel Structure ◽  
Proper Function ◽  
High Speed Train ◽  
Practical Application ◽  
Specific System ◽  
Reliability Allocation ◽  
Current Collection ◽  
Minimum Number

The paper deals with the possibilities of allocating reliability requirements for a system using complex redundancy. It means system consists of a few identical subsystems and for its common function it is quite enough if only certain part of these subsystems operates. The subsystems not operating at a certain moment serve as redundancy in case that the subsystems which are operating fail. All the system, however, is not a trivial parallel structure, because if the system is to work properly, always more than one subsystem should operate and the subsystems can function only in configurations set in advance. Practical application of the suggested method of reliability allocation is demonstrated for a pantograph system of a high-speed train. In order to provide the proper function of the system, the minimum number of operating pantographs in pre-set configurations providing safe current collection has to be always available. Using some pantograph configurations (e.g. two pantographs being one after another very closely) is in fact not possible for safety reasons. The article presents the procedure of reliability allocation for this specific system. Suggested method is based on a truth table and Boolean algebra application.

scholarly journals Analysis of Effect of Pantograph Cover on the Current Collection Quality of High Speed Train using Real Train Experiment

2016 ◽  
Vol 19 (4) ◽  
pp. 409-416
Author(s):  
Hyuck Keun Oh ◽  
Seogwon Kim ◽  
Yong-hyun Cho ◽  
Minho Kwak ◽  
Sam Young Kwon
Keyword(s):  
High Speed ◽  
High Speed Train ◽  
Current Collection

Influence of a high-speed train passing through a tunnel on pantograph aerodynamics and pantograph–catenary interaction

2016 ◽  
Vol 231 (2) ◽  
pp. 198-210 ◽  
Author(s):  
Ruiping Li ◽  
Weihua Zhang ◽  
Zhou Ning ◽  
Binbin Liu ◽  
Dong Zou ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
High Speed ◽  
Aerodynamic Drag ◽  
Contact Forces ◽  
Blockage Ratio ◽  
High Speed Train ◽  
Aerodynamic Forces ◽  
Current Collection ◽  
Uplift Forces

Aerodynamics of trains running inside tunnels change more significantly in comparison with open air scenarios. It has been confirmed that the lateral vibration as well as the aerodynamic drag of the trains is increased and the micro-pressure wave is produced at the tunnel exit when the trains are passing through tunnels. The aim of this article is to explore the impact of a high-speed train passing through a tunnel on the pantograph aerodynamics and the dynamic behavior of the pantograph–catenary interaction. The aerodynamic forces acting on the pantograph are investigated thoroughly by extensive numerical simulations as well as systematic field tests. To investigate the effects of the aerodynamic forces of pantograph on the quality of current collection, the numerical simulations of the pantograph–catenary dynamic interaction are conducted with our proposed model, taking into consideration the action of the aerodynamic uplift forces obtained by the numerical simulations on the pantograph. Then, a series of numerical simulations are also carried out to analyze the effects of the train speed and the blockage ratio on the aerodynamic uplift forces of the pantograph, on the contact forces, as well as on the displacement of the contact wire, while the train is passing through a tunnel. The results reveal that compared with the open air scenarios, the aerodynamic drag and uplift forces of the pantograph, the mean value of the contact force and the displacement level of the registration arm can considerably increase as the train runs inside a tunnel. Moreover, the statistical values of the contact forces and the displacement level of the contact wire become larger while the train is passing through the tunnel at different speeds. On the other hand, the quality of current collection decreases with the increasing of the blockage ratio.

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