Track circuits’ robustness: Modeling, measurement and simulation

Projekt:

JVTC

Sammanfattning:
In countries with rough weather conditions, frequent delays cause railway
companies to waste time and money. Many of these delays are related to the
train detection systems, as the old DC track circuits are still used in some
countries, including Sweden, our case study. Since the most important factor in
the railway system is safety, in some cases, the train detection system gets
incorrect information and detects a non-existent train. The train slows down to
avoid a problem in the track (with other trains or other faults), causing
prolonged delays with cascading effects. The analysis in this licentiate
contributes to the detection and reduction of TC failures; this, in turn, will save
money for the railway community.

A classification of the most probable causes of failures related to the train
detection system was derived from the Swedish failures report database 0FELIA.
After classifying failures, we focussed on the three most common worst case
scenarios: low resistance between the rails, external interference such as a
lightning strike, and iron-powder-bridges in the insulated joint.

Electromagnetic interferences (EMI) are a problem for the railway system in
general. One source of electromagnetic (EM) transients is the return current
harmonic produced by the engine of the rolling stock itself. In the first stage of
this licentiate, we implemented a Matlab model of the power supply system of
the Swedish railway infrastructure, using the characteristics and previous
measures of a real source. A model of a train as an active load validated by the
manufacturer was integrated as a subsystem in different positions of the
infrastructure. This method was used to study the behaviour of the low
frequency system from an electrical point of view but it could also be used as
input for an electromagnetic model using high frequencies. The model was
validated through measurements taken in northern Sweden.

In addition, a 3D model of the whole railway system was proposed. The
simulation software was CST STUDIO SUITE® (Computer Simulation
Technology Studio Suite), supported by real measurements on site and the lab
to tune and validate the model. The results of the simulation show that the
model fits with reality and is reliable for the study of track circuit sections.

Some measurements followed the current standards, but we also analysed points
not covered by them, allowing us to update the current standards

Författare: Emilio Rodriguez
Utgivare: Luleå tekniska universitet
Utgivningsdatum: 2014-11
Diarienummer: TRV 2011/58769
ISBN: 978-91-7583-045-2
ISSN: 1402-1757
Antal sidor: 244
Språk: Engelska
Kontaktperson: Per Olof Larsson Kråik, UHjbs