ALIS: Simulation tool for the rail electrification environment
The railway sector, which is booming on an international level, is faced with challenges concerning optimal, safety and sustainable designs. This calls for the need to develop an innovative tool like ALIS, in which -for the first time- integration in the electrification design, passenger safety and the safety of the installations, and energy efficiency both in terms of design and operation, provide for the integration of renewable energy sources.
Due to the soaring growth in rail electrification projects, their increasingly high technical demands, an awareness of safety requirements of people and their surroundings and the trend in safe and sustainable designs, there is a need for an engineering tool to be developed that can address these needs, whether they be present or future, in the international rail market.
On the other hand, we must keep in mind that there is an awareness with regards to reducing environmental emissions which is increasingly leading to smart network designs or Smart Grids, whose main objective is to apply efficient forms of energy consumption, improving sustainability and furthering continuous improvement in the integration of sources of generation of renewables.
“All the technical difficulties that come up in railway electrification designs are covered by our innovative simulation tool (ALIS).
And so ALIS was born: intelligent application algorithm tool for rail electrification environment simulation. It is flexible and capable of performing simulations that take any type of catenary technology into account, both in alternating current (AC) as well as direct current (DC).
The first large ALIS block models, in electrical terms, actual rail system consumption which covers the simulation of the train’s dynamic performance, dimensioning of the traction substations right up to the optimum substation location along a line. In addition, in mechanical terms, it simulates the pantograph-catenary interaction for a train traveling at any speed, and obtains all the contact forces involved. Due to the fact these types of mechanical studies are possible, the standardizing of different catenary designs also becomes possible which in turn, will enable Abengoa to gain an important competitive edge in the sector. Thanks to the block’s robustness and considerable flexibility, an intelligent design is possible based on the operating and defining criteria of all the rail systems’ integrated components.
The second of the large ALIS blocks is comprised of the safety of the railway environment, together with the workers and passengers. For this, the imbalances which are caused by the operation of the rail system are modelled. In addition, stress induced (electromagnetic interference) in parallel and crossed lines, whether they be for communication, track circuits or any electrical line, with a view to reducing interference that result from electromagnetic fields. Furthermore, density diagrams relating to the electromagnetic field produced by the railway installations can also be made up that are based on the availability of conductors in the catenary, as can be seen in the image below.
“ALIS can simulate electronic fields in rail electrification systems and offers the possibility of mitigating potential adverse impacts.
Specifically, in relation to emissivity of electromagnetic fields in rail systems, in accordance with the World Health Organization (WHO), for those which are extremely low (50/60 Hz) and are produced by railway electrification lines, it is advisable that medium/long term exposure to magnetic fields does not to exceed 0.3-0.4 µT. (Briefing note Nº322 – June 2007 – WHO).
Last of all, the third large ALIS block covers the sustainability and energy efficiency applied to rail systems. Thanks to the intelligent innovative and integrated optimization algorithms that are used, the simulation of efficient train gears is possible thus reducing energy consumption, as well as scheduling optimization with the goal of energy minimization. In fact, according to the strategic lines set out in the Innovation and Infrastructure Transport Plan (Ministry of Development) for 2017-2020, progress towards the use of renewable energies, and the storage and redistribution to the network of the energy generated by the transport network leads to more sustainable and efficient transport systems.
In this sense, ALIS allows an optimal storage system to be dimensioned in the face of the operation of trains with the goal of integrating them to take advantage of the regenerative braking while taking into account parameters like Pay-Back (the timeframe for a return on investment) and the number of cycles throughout the entire life cycle of these systems.
It is also important to emphasize that ALIS integrates an innovative optimization algorithm which provides for the integration of renewable energies to join with storage systems and the train’s regenerative breaking, therefore allowing an analysis of the energy impact to be performed that has all of these elements integrated -as a whole- into the railway electric system. We must highlight the high complexity of this analysis and the great advantage that has been gained with this tool’s development.
This project has been developed by Abengoa together with Madrid Polytechnic University and Malaga University, along with an excellent team, places Abengoa in the leading position when it comes to the intelligent design, safety and sustainable systems of railway systems.