Business lines

> Transport > Railway electrification

Railway Electrification


High-Speed Railways

SEMI is a leading company in the design and development of high-speed catenary system implemented by Spanish Rail Administration, in accordance with the most recent European interoperability specifications.

The C-350 catenary is an electric feeding system for high-speed railways with the official approval of the EU, according to the “Technical Specification for Interoperability (TSI)”, which allows train operation at 350 km/h speed, with power supply of 1x25 kV CA and 2x25 kV CA.

Conventional Railways

The company has contributed to the electrification development of Spanish conventional rail lines, to their projects and installation, with speeds of up to 220 km/h, and power supply of 1,5 KV CC and 3 kV CC.

Nowadays SEMI’s experience allows us to perform any task in this field, from the design and project to the installations and their maintenance.

SEMI’s background within this field has allowed the company to specialize in conventional lines upgrade and modernization, reliability improvements, and acceptable speed increase.

Among our different developments is the polyvalent catenary with DC/AC power supply.


Underground, tramways, and metropolitan railways

The experience in this field allows us to perform the design, project, installation and maintenance necessary for the electrification of suburban trains, tramways or undergrounds with speed of up to 120 km/h, and feeding voltage level of750 V CC, 1,5 kV CC and 25 kV CA.

This activity includes the use of specific solutions, such as rigid catenary or Phantom-type catenary cable compensation. 

Traction substations

SEMI constructs electric traction substations, rectifier substations of alternating current/direct current in a wide range of feeding voltages and uses, in accordance with levels established by railway authorities.

The company develops projects with valid technologies in the following fields:

  • AC feeding
  • Transformation
  • Rectification
  • Feeders
  • Control

Classification of the main types of installed substations:

  • 3,300Vcc rectifier-transformer substations  - Conventional control system
  • 3,300Vcc rectifier-transformer substations  - Distributed control system
  • 1,500Vcc rectifier-transformer substations  - Conventional control system
  • 600 Vcc rectifier-transformer substations 
  • 220-400 Kv / 2x25 kV ca transformer substations
We use first and third party cookies to improve the user’s experience of the website. By using this site you agree with the terms of this policy