Analysis of energy A. López López 1 ; R. Rodríguez Pech Cardador 5 (1, 2, 3, 4, 5) Institute for Research Comillas Pontifical U (3) Multitest09. Madrid, S Abstract This paper presents some results o mainly developed for studying energ Two case studies have been carried assessing the energy saving related reversible substations, etc. The seco improvements due to the introductio /-75kV electrification are analyzed. Key words Railway electrification, energy efficie 1. Introduction Railway operators are always lookin where it is up to be evaluated how m represents a significant fraction of the Analytically dealing with an electric non-linear (especially in the DC railw where loads are constantly changing simulator is the most suitable tool electrical simulator is a key point fo lines where electric traction is used. The aim of this work is to compare d of railway systems: usage of train b rectifier and inverting substations technologies are already available, combined improvements. The energy consumption will be an thus improving investment decisions and/or an increment in the capacity. 2. Simulator Features The simulator makes it possible to an In the DC side, the simulator feature consumption point of view:  Regenerative Braking: Both resistors or returning it into th  Reversible Substations: Mos unidirectional, i.e. they only are reversible substations w flow from the AC to the DC substations.  Energy Storage Devices: Pr energy storage is sometime Challenge A: A more and more energy y-saving strategies in railway p supply systems harromán 2 ; E. Pilo de la Fuente 3 ; A.P. Cucala 4 , A. F h in Technology. ICAI School of Engineering. University. Madrid, Spain. Spain. obtained with an electric railway simulator. This gy consumption in both AC and DC electrified ra d out. The first one analyzes a DC electrified under with the introduction of trains equipped with regen ond case study consists in an AC electrified high sp on of regenerative braking, capacitor banks and en ent, load flow, railway power supply ng for a reduction in their operative costs. One of much money may be saved is the energetic bill, wh e total costs (especially in underground and comm railway problem is rather hard: first, these probl way case); then, they are in addition complex time-v g their values and positions. For these reasons, in for handling such a complex system. It may be or the study and management of energy consum different possibilities of saving energy regarding th braking regeneration, off-board energy storage, ca for DC railways, impact of voltage supply lev but there is a need of analyzing their impact bo nalysed for each possibility in the same line and s. The final purpose is to achieve a more energy e nalyze DC, AC and mixed AC-DC electrified railwa es the electrical models of the main components h the possibilities of dissipating braking energ he network (when possible) are considered. st of today electrical substations in DC-electrified ra allow power to flow from the AC to the DC side. which work in two electrical quadrants hence allo C side and vice-versa. The simulator permits usin rovided in a railway system the consumption is fair es a key factor for energy saving. In addition, thes efficient railway power Fernández- s tool has been ailway systems. rground system, nerative braking, peed line where nhanced +25kV f the cost items hich sometimes muter systems). lems are highly variant systems n most cases a stated that an mption in railway he electrification apacitor banks, vel, etc. These oth as single or circumstances, efficient railway ay lines. from an energy gy in dedicated railway lines are However, there owing current to ng both kinds of irly time-variant, se devices may