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Civil-Comp Proceedings
ISSN 1759-3433
CCP: 98
Edited by: J. Pombo
Paper 176

A New Approach to the Assessment of the Unbalance Produced by Railway Networks

J. de D. Sanz Bobi and R. Loiero

CITEF - Research Centre on Railway Technologies, Polytechnic University of Madrid, Spain

Full Bibliographic Reference for this paper
J. de D. Sanz Bobi, R. Loiero, "A New Approach to the Assessment of the Unbalance Produced by Railway Networks", in J. Pombo, (Editor), "Proceedings of the First International Conference on Railway Technology: Research, Development and Maintenance", Civil-Comp Press, Stirlingshire, UK, Paper 176, 2012. doi:10.4203/ccp.98.176
Keywords: high speed rail network, power quality, unbalance emission level, voltage unbalance, electromagnetic compatibility.

This paper presents three different methods to calculate the voltage unbalance in the AC high speed lines of a railway network. The methods are explained using as example the high speed line Rio de Janeiro - São Paulo, between Barão de Mauá Station and Campinas Station.

The first method considers the approximated formula presented in the IEC Standards [1,2,3]. The second method, named the complex power method [4], calculates the voltage unbalance using the active and reactive power of both transformers present in the substation of the example. The third method is based on the symmetrical components oriented to impedances.

The application of the classical formula presented in the IEC Standards has demonstrated the approximate nature of its use, since there is no consideration of the real use of transformers during the operation of the line.

Using the power complex method and the symmetrical component method, three situations are shown: voltage unbalance every 1 second, every 30 seconds and every 10 minutes. This method allows one to calculate in the time domain the voltage unbalance and hence there is the possibility to compare the values with the ranges imposed by the national requirements [5]. Besides, they represent a tool to make a comparison with IEC 6100-4-30 [6]. In this way the complex power method and the symmetrical method could be a way of determining if the considered railway system complies with the national and international requirements before measuring the voltage unbalance directly.

EN 50160:2010, "Voltage characteristics of electricity supplied by public electricity networks".
IEC 61000-2-2:2002, "Electromagnetic compatibility (EMC) - Part 2-2: Environment - Compatibility levels for low-frequency conducted disturbances and signaling in public low-voltage power supply systems".
IEC 61000-2-12:2003, "Electromagnetic compatibility (EMC) - Part 2-12: Environment - Compatibility levels for low-frequency conducted disturbances and signaling in public medium-voltage power supply systems".
J.G. Mayordomo, L.F. Beites, J.L. Gutiérrez, "Assessment of Unbalance Emission Level Produced by Loads Using the Apparent Power Components", Publicado en la revista ETEP, 6(6), Nov/Dec 1996.
"Instalaciones conectadas a la red de transporte peninsular: requisitos mínimos de diseño y equipamiento", Red Eléctrica de España, May 2010.
IEC 61000-4-30:2008, "Electromagnetic compatibility - Part 4-30: Testing and measurement techniques - Power quality measurement methods".

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