Page 67 - 360.revista de Alta Velocidad - Nº 5

Current situation and prospects of electric traction systems used in High-Speed railways

Figure 11. Coaxial cable feeding system. (Source: [2]).

6. TPS of the Madrid-Seville High-speed line: current situation and possible future

At the moment Adif is analyzing the operational advantages that the implantation of new
power electronics (Full-Power Converter) in the electric traction substations of the High-
Speed line Madrid-Seville would have. It must be considered that these substations have
not been modified since the opening of the line (1992) and the current high traffic density
recommends analyzing the impact that this new technology could have on the operation of
the line.
The main action will be the determination of the design of the converter that allows the flow
of energy between the public three-phase network and the single-phase rail network. The
objectives are two: to analyze a possible improvement in the affection to the grid; to analyze
possible improvements in the power supply to trains, including possible elimination of neutral
zones in the catenary.
This High-Speed line has a 1 x 25 kV (simple feeding with rail return system). There are 11
substations with the average distance of 40 km between substations. Each substation has two
single-phase 20 MVA transformers connected to the same two phases and three power outputs
(one for each direction and another for a section of track in front of the substation itself of
approximately 2 km). There are only neutral sections between substations, and there is no
neutral section in front of the substation. The tracks are connected in parallel approximately
every 10 km by use of disconnectors. The auxiliary systems of the line (technical building,
radio stations for mobile communications, tunnel lighting and switch heater) are powered by
transformers connected to the catenary.

The substations of this line are connected to the grid with nominal voltages between 132
kV to 220 kV, which have a comparably lower short-circuit power availability than very high
voltage networks with up to 220 kV to 400 kV.

International Congress on High-speed Rail: Technologies and Long Term Impacts - Ciudad Real (Spain) - 25th anniversary Madrid-Sevilla corridor 65