595 research outputs found
Application of Weighted Fuzzy Reasoning Spiking Neural P Systems to Fault Diagnosis in Traction Power Supply Systems of High-speed Railways
This paper discusses the application of weighted fuzzy reasoning spiking neu-
ral P systems (WFRSN P systems) to fault diagnosis in traction power supply systems
(TPSSs) of China high-speed railways. Four types of neurons are considered in WFRSN P
systems to make them suitable for expressing status information of protective relays and
circuit breakers, and a weighted matrix-based reasoning algorithm (WMBRA) is intro-
duced to fulfill the reasoning based on the status information to obtain fault confidence
levels of faulty sections. Fault diagnosis production rules in TPSSs and their WFRSN P
system models are proposed to show how to use WFRSN P systems to describe different
kinds of fault information. Building processes of fault diagnosis models for sections and
fault region identification of feeding sections, and parameter setting of the models are
described in detail. Case studies including normal power supply and over zone feeding
show the effectiveness of the presented method.Ministerio de EconomĂa y Competitividad TIN 2012-373
Contractors as modern Master Builders: Virtual Design and Construction as an enabler of meaningful experiences to project teams for achieving optimized substation management
Effective substation management should include engineering and construction costs. While the construction process has to be methodically planned
and sequenced to achieve optimized construction costs, substation designers play a vital role for delivering cost-efficient substations. Integrated
design and construction has been proposed as a way to achieve effective project management, which historically viewed, was a responsibility of a
“master builder”, thus causing Contractors to identify themselves as “master builders”.
As EPC is a highly competitive arena, Contractors are looking for ways to differentiate themselves from their competitors. Some are turning to 3D
technologies, while others turn to the design-construction integration. Virtual Master Builder (VMB) supports both 3D technologies and the designconstruction
integration. Due to a global shortage of worldwide available expertise, Contractors turn to education and training of their employees.
While education aims at providing basic skills, training aims to provide the skill necessary to do the job. This paper examines these basic skills as a
part of personal mastery before defining organizational learning as a key organizational competence.
Physical Virtuality realm is seen as a fruitful ground for staging of memorable and transformational experiences leading towards achieving “accelerated
learning”, and especially 4D models as representations of a “space-time” environment. The project case of Skopje 4 SS 380/110 kV rehabilitation
is given as an example of 4D models usage. Project Engineering is seen as a middle ground between engineering and management in order to
achieve goals of effective substation management and cost-efficient substation solutions. Project teams are seen as Virtual Design and Construction
(VDC) users to achieve these goals
Configuration Detection of Grounding Grid: Static Electric Field Based Nondestructive Technique
Grounding grid configuration which, is key to its fault diagnosis, changes continuously with the extension in a substation. Furthermore, older substations grounding grid configurations are unknown. Existing literature regarding configuration detection mainly accounts for the magnetic field that required a gradient to locate the grounding conductor. The gradient of raw measurement in the substation vicinity enhances electromagnetic noise and distorts the results. Therefore, in this paper, we have developed a new algorithm, Configuration Detection of Grounding Grid (CDGG) based on the static electric field and the concept of ordered pairs to draw the configuration of the unknown grounding grid. Unlike, the practiced magnetic field, the electric field does not require a gradient. The maximum electric field value indicates the location of a grounding conductor. The connection between nodes is verified by measuring the electric field on the circle. Furthermore, the proposed algorithm also locates any diagonal conductor in the configuration. Mathematical reasoning and simulation results illustrate that our proposed algorithm is feasible to draw the configuration of the unknown grounding grid
Infrastructure Design, Signalling and Security in Railway
Railway transportation has become one of the main technological advances of our society. Since the first railway used to carry coal from a mine in Shropshire (England, 1600), a lot of efforts have been made to improve this transportation concept. One of its milestones was the invention and development of the steam locomotive, but commercial rail travels became practical two hundred years later. From these first attempts, railway infrastructures, signalling and security have evolved and become more complex than those performed in its earlier stages. This book will provide readers a comprehensive technical guide, covering these topics and presenting a brief overview of selected railway systems in the world. The objective of the book is to serve as a valuable reference for students, educators, scientists, faculty members, researchers, and engineers
Railway interference management: TLM modelling in railway applications
This thesis deals with the application of analytical and numerical tools to
Electromagnetic Compatibility (EMC) management in railways. Analytical
and numerical tools are applied to study the electromagnetic coupling from an
alternating current (AC) electrified railway line, and to study the electrical
properties of concrete structure - a widely used component within the railway
infrastructure. An electrified railway system is a complex distributed system
consisting of several sub-systems, with different voltage and current levels,
co-located in a small area.
An analytical method, based on transmissions line theory, is developed to
investigate railway electromagnetic coupling. The method is used to study an
electrified railway line in which the running rails and earth comprise the
current retum path. The model is then modified to include the presence of
booster transformers. The analytical model can be used to study the railway
current distribution, earth potential and electromagnetic coupling - inductive
and conductive coupling - to nearby metallic structures. The limiting factor
of the analytical model is the increasing difficulty in resolving the analytical
equation as the complexity of the railway model increases.
A large scale railway numerical model is implemented in Transmission Line
Matrix (TLM) and the electromagnetic fields propagated from the railway
model is studied. As this work focuses on the direct application of TLM in
railway EMC management, a commercially available TIM software package is
used. The limitation of the numerical model relates to the increased
computation resource and simulation time required as the complexity of the
railway model increases.
The second part of this thesis deals with the investigation of the electrical
properties of concrete and the development of a dispersive material model
that can be implemented in numerical simulators such as TIM. Concrete is
widely used in the railway as structural components in the construction of
signalling equipment room, operation control centres etc. It is equally used as
sleepers in the railway to hold the rails in place or as concrete slabs on which
the whole rail lines are installed. It is thus important to understand the
contribution of concrete structures to the propagation of electromagnetic
wave and its impact in railway applications.
An analytical model, based on transmission line theory, is developed for the
evaluation of shielding effectiveness of a concrete slab; the analytical model is
extended to deal with reinforced concrete slab and conductive concrete. The
usefulness and limitation of the model is discussed. A numerical model for
concrete is developed for the evaluation of the effectiveness of concrete as a
shield. Initially, concrete is modelled as a simple dielectric material, using the
available dielectric material functionality within TLM.
It is noted that the simple dielectric model is not adequate to characterise the
behaviour of concrete over the frequency range of interest. Better agreement
is obtained with concrete modelled as a dispersive material having material
properties similar to that exhibited by materials obeying Debye equation. The
limitations of the dispersive material model are equally discussed.
The design of conductive concrete is discussed, these have application in the
railway industry where old existing structures are to be converted to
functional rooms to house sensitive electronic system. A layer of conductive
concrete can be applied to the facade to enhance the global shielding of the
structure
DC railway power supply system reliability evaluation and optimal operation plan
With the continuous and rapid development of the economy and the acceleration of urbanisation, public transport in cities has entered a period of rapid development. Urban rail transit is characterised by high speed, large traffic volume, safety, reliability and punctuality, which are incomparable with those of other forms of public transport. The traction power supply system (TPSS) is an important part of an electrified railway, and its safety issues are increasingly prominent. Different from the substation in a general power system, the load of a TPSS has a great impact on the traction transformer; moreover, in order to ensure normal operation of the train in case of failure, the traction substation must be able to access a cross-district power supply, as it has a high demand for reliable operation. The safe and reliable operation of DC TPSSs is the basis of the whole urban railway transit system.
Previous studies have investigated the reliability of the TPSS main electrical wiring system. However, the impact of traction load and the actual operation of trains on system reliability has not been considered when designing a DC railway power supply system. The purpose of the research for this thesis is to find an optimal system operation plan for urban railways, considering load characteristics.
This thesis begins with a review of the main arrangements of DC railway power supply systems and the literature on railway reliability studies. A model of single train simulation and a power supply system is established in MATLAB. The developed simulator is then integrated with a TPSS reliability model to evaluate the energy and reliability performance of DC railway power systems. Based on the train traction load model and train schedule, a comprehensive method for evaluating a DC TPSS considering traction load is proposed. Through simulation of the actual operation of the train group, the system energy consumption and substation life loss generated under different train operation diagrams and schedules are compared to provide a reference for the reasonable design of the timetable. Taking the life loss and energy consumption of the whole TPSS as the objective function, a genetic algorithm is used to optimise the train speed, coasting velocity, station dwell time and headway to find the optimal operation strategy. This is illustrated with a case study of the Singapore East–West metro line.
The study has addressed the following issues: development of a multi-train power simulator, evaluation of reliability performance, and finally the search for an optimal operation plan. The train running diagram and timetable are optimised jointly. This can help railway operators make decisions for an optimal operation plan and reduce the operation risk of the power system
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