Optimizing the calculation of energy consumption for Tramway Networks

Sistema de prevencion de viento lateral-ferrocarril-sice
Sistema de prevencion de viento lateral-ferrocarril-sice

IDOM is working on optimizing the calculations of the electrical installations of tramway networks using the reps (railway electrical power simulator) tool.

REPS is a specialized software tool, developed entirely by the IDOM R+D+I team, for the simulation and analysis of railway electrical networks, together with the analysis of the planned operating grids. This software has been used in the design of the Tramways of Bilbao, Murcia and Zaragoza (Spain), Lund (Sweden), and Ring 3 Copenaghe (Denmark).

The design of electrical installations for a tram network, especially substations requires a great deal of adjustment, to minimize the size and insertion of the substations in the city. Also factors such as EMC (electromagnetic fields) and energy regeneration are key aspects to be considered when designing in an urban environment.

The REPS simulator developed by IDOM has a powerful Graphical Interface to visualize / interact all the elements, creating different scenarios on the tram network and on the electrical system and analysing an endless number of operations situations, even in degraded mode. The entire tramway network is simulated at once, both electrically and with different variants of the grid operations.

The electric model is adjusted to real values measured during existing operations and can be calibrated with real measurements for each client in the case of in-service trains.

The main innovations that have been incorporated into the software for the analysis of the tram networks with respect to other conventional models of energy analysis are:

  1. Bi-directional substations can be set up, in order to achieve a preliminary analysis of the recovery of braking energy systems, determining the return to the electric network. With this feature, the installations can be designed taking into account the energy recovery and the power of the equipment of return of energy to the network, thereby reducing the installed power.
  2. The tool also integrates a module to calculate the currents in the overhead contact line, with continuous recording serving as input data for the calculation of electromagnetic fields. This allows electromagnetic compatibility (EMC) analysis in frequency ranges outside the regulatory analysis (between 0 and 9 kHz), which could affect sensitive equipment, typically located in hospitals, universities or scientific centres, which may be located close to tram networks.
  3. The capacity of stored energy can be evaluated for the units required to circulate in “Free Catenary” sections or without contact line (system with batteries in the rolling stock).
  4. The energy quality of a line can be analyzed, calculating the losses by the Joule effect in conductors as well as the percentage of energy burned in them, in relation to all the energy supplied.

The implementation in the IDOM calculation algorithms tool, highly optimized, reduces the analysis times, allowing the entire alignment to be evaluated, in reduced periods of time and obtaining a more global and detailed analysis of everything related to the energy supply of tramway infrastructure projects.