DC traction power supply system

Experience high performance

An age of extreme urbanization calls for innovative and flexible mobility concepts. With our long-standing transport and IT expertise, we’re always developing new, intelligent mobility solutions that increase availability of infrastructure, optimize throughput, and improve the passenger experience. Benefit from our decades of experience in engineering, construction, and commissioning of DC traction power supply systems. We provide all the services you need from a single source, creating valuable synergies in the process and giving you unique opportunities to save costs.

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Modular portfolio

DC traction power supply – high-performance, efficient, and safe

Reduce costs and save resources using efficient, resilient traction power supply systems. Our end-to-end modular portfolio of converters, DC switchgear, and protection systems lets you operate your rail systems with confidence – and with top performance, efficiency, and safety.

High-performance DC traction power supply: The system and its components

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Medium-voltage switchgear

Reliable operation

Distribute energy feeds efficiently and connect them reliably with the rectifier group, regardless of whether you select a gas or air-insulated indoor installation.

Medium-voltage switchgear for the DC traction power supply system

For our DC substations, we use the same proven standard medium-voltage switchgear used by utilities and industrial plants. The prefabricated type-tested equipment with air or gas insulation complies with all national and international standards and guarantees the highest level of safety for operating personnel.

Rectifier group

Achieve maximum cost-effectiveness

A secure power supply for your contact lines: Reduce your voltage with transformers from Siemens and use rectifiers to convert AC to DC current.

Rectifier transformers for the DC traction power supply system

Designed especially for highly dynamic rectifier loading, our rectifier transformers have power ratings that range from approximately one MVA for stations supplying trolley cars and trams to approximately seven MVA for operating heavy subways. Standard oil-insulated or industry-proven cast-resin transformers are used that also fulfill special requirements for fire protection and safety.

Sitras REC diode rectifiers for the DC traction power supply system

Sitras REC type rectifiers are designed to supply traction power to DC-operated mass transit systems and main-line railways. The special demands of these rail services are met by air-cooled disc-type diodes with a high blocking voltage.

 

Your benefits:

  • Modular design allows cost-effective modification to customer requirements
  • Compact design
  • High capacity, high overload capability
  • Type-tested to IEC 60146-1-1 and EN 50328
  • Reliably low maintenance requirements as a result of robust mechanical and electrical design
  • Earthquake-tested versions available
Sitras REC diode rectifiers

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Sitras REC-W withdrawable diode rectifiers for DC traction power supply

These withdrawable diode rectifiers are designed to supply traction power to DC-operated rail systems. The Sitras REC-W is based on the service-proven series of fixed-mounted diode rectifiers using air-cooled disc-type diodes with a high blocking voltage.

 

Your benefits:

  • Optimized design for combined installation with Sitras DSG DC switchgear
  • Compact dimensions due to eliminating the incoming/return line panel for the DC switchgear
  • Easy maintenance thanks to withdrawable truck
  • High capacity, high overload capability
  • Type-tested to IEC 60146-1-1 and EN 50328
  • Reliably low maintenance requirements as a result of robust mechanical and electrical design
Sitras REC-W withdrawable diode rectifiers

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Sitras PCI self-commutated IGBT inverter for DC traction power supply

Thanks to a reduction in primary energy consumption, DC substations equipped with the Sitras PCI type of self-commutated IGBT inverters make a crucial contribution to reducing CO2 and energy costs.

 

Your benefits:

  • Existing substations can be retrofitted by installing a Sitras PCI
  • Option for remote parameterization, control, and diagnosis via standardized communication interface
  • Tried and tested IGBT technology used in Siemens rail vehicle construction
Sitras PCI self-commutated IGBT inverter

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DC switchgear

A stable power supply

Sitras DSG and Sitras CSG metal-enclosed DC switchgear: providing your DC rail network with a stable power supply.

Sitras DSG DC switchgear for DC traction power supply

The Sitras DSG DC switchgear is used in the power supply for DC railways in mass transit and main-line systems. Sitras DSG is a type-tested, metal-enclosed, compartmented switchgear unit for indoor installation and meets all the demands placed on today’s DC traction power supply systems.

 

Your benefits:

  • Low life-cycle costs due to low maintenance requirement and resistance to environmental influences
  • Small space requirement because all components are easily accessible
  • Safe and reliable, as verified by type tests in accordance with EN 50123-6 and IEC 61992-6
  • Arc-fault tested and earthquake-tested versions available
  • Flexible thanks to modular design of panels
Sitras DSG DC switchgear

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Sitras CSG compact DC switchgear for DC traction power supply

The Sitras CSG DC switchgear is designed for use in the power supply for DC vehicles in mass transit systems, trams, and trolley cars. Sitras CSG is a type-tested, metal-enclosed indoor switchgear unit with an integrated diode rectifier. It’s designed for DC traction power supply systems with low to medium power ratings.

 

Your benefits:

  • Very small space requirement due to extremely compact design and unrestricted suitability for wall mounting
  • Optimized cost/benefit ratio thanks to demand-oriented design and high degree of standardization
  • Low life-cycle costs due to low maintenance requirements and resistance to environmental influences
  • Safe and reliable, as verified by type tests in accordance with EN 50123-6 and IEC 61992-6
Sitras CSG compact DC switchgear

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Protection

Always on the safe side

Proven protection for contact lines, future-proof and easy to operate: Sitras PRO and Sitras MDC provide protection and control functions and flexible communication.

Modular digital controller: Sitras MDC DC protective unit and controller for DC traction power supply

The Sitras MDC modular digital controller is used in the power supply of DC railways in mass-transit and main-line systems up to 3,000 V DC. As a DC protection unit, it protects DC switchgear and contact line systems from critical operating conditions and detects short circuits during a current rise – even before maximum short-circuit currents are reached.

 

Your benefits:

  • Complete functionality in a single unit:
    – Protection
    – Measurement
    – Control unit
    – Automation
    – Freely programmable PLC
    – Integrated switch functions
  • Flexible adaptation to system requirements
  • Standard communication interfaces
  • High-performance diagnostics, comprehensive event and measured-value memory
  • Complies with all relevant standards
  • Modular hardware and software design
Sitras MDC modular digital controller

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Sitras PRO combined protection unit and controller for DC traction power supply

The Sitras PRO combined DC protection unit and controller is used in the power supply for DC railways in mass transit and main-line systems up to 3,000 V DC. It protects DC switchgear and contact line systems from critical operating conditions and detects short-circuits during a current rise – even before maximum short-circuit currents are reached.

 

Your benefits:

  • Complete functionality in a single unit
    – Protection
    – Measurement
    – Control
    – Automation
  • Flexible adaptation to system requirements
  • Standard communication interfaces
  • High-performance diagnostics, comprehensive event, alarm, and measured-value memory
  • Compliance with all relevant standards
Sitras PRO combined protection unit and controller

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Sitras SCD short-circuiting device for DC traction power supply

In DC traction systems, impermissible contact voltage can occur between the return circuit and the structure ground due to operational currents and short-circuit currents. The persistence of these voltages must be prevented by a voltage-limiting device in accordance with IEC 62128-1/EN 50122-1. Sitras SCD reduces excessively high voltage by reliably short-circuiting the return circuit and structure ground temporarily. The formation of stray currents is also minimized by automatically opening the short-circuiting device.

 

Your benefits:

  • Fulfills all the criteria of IEC 62128-1/EN 50122-1
  • Optional evaluation of combined voltages fulfilling all requirements specified by EN 50122-3
  • Operational safety and reliability due to high current carrying capacity and type-testing in accordance with EN 50526-2
  • Maximum protection of personnel and equipment thanks to rapid response time
  • High functionality and ease of use due to programmable controller with intuitive control board earthquake-tested versions available
Sitras SCD short-circuiting device

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Sitras SCD-C compact short-circuiting device for DC traction power supply

In DC traction systems, impermissible contact voltage can occur between the return circuit and the structure ground due to operational currents and short-circuit currents. The persistence of these voltages must be prevented by a suitable voltage-limiting device in accordance with IEC 62128-1/EN 50122-1. Sitras SCD-C reduces excessively high voltage by reliably short-circuiting the return circuit and structure ground temporarily. The formation of stray currents is also minimized by automatically opening the short-circuiting device.

 

Your benefits

  • High protection for personnel ‒ rapid response time fulfills EN 50122-1 over the entire time range down to 20 ms
  • Operational safety and reliability verified by type testing in accordance with EN 50526-2
  • Cost-effective thanks to demand-oriented design and very high degree of standardization
  • Very small space requirement due to compact design and wall mounting
  • Earthquake-tested version also available
SCD-C compact short-circuiting device

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Local charging units

Fast and safe charging

The Sitras LCU and Sitras LCU-C local charging units quickly recharge mobile energy storage systems on railway vehicles.

Sitras LCU and Sitras LCU-C local charging units for DC traction power supply

The Sitras LCU local charging unit and the Sitras LCU-C compact charging unit quickly charge mobile energy storage systems on railway vehicles. Recharging occurs during dwell time via the overhead conductor rail. Sitras LCU can be placed at stations or stops or can be integrated into traction substations. Additionally the diode box of the Sitras LCU-C can be installed in any location – including outdoor or underground. 

 

Your benefits

  • Concept for highest safety and availability of the entire system for operating with no overhead contact line
  • High charging currents enable charging during typical dwell periods
  • Based on proven Sitras products for DC traction power supply
  • Integrated auxiliary power supply for the station / stop
  • Project-specific dimensioning possible; also for the compact type Sitras LCU-C (without auxiliary power supply)
Sitras LCU local charging unit

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Sitras LCU-C local charging unit

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Experience high performance – with the DC traction power supply

Benefit from our decades of experience in the engineering, construction, and commissioning of DC traction power supply systems. We provide all the services you need from a single source, giving you unique opportunities to save.

Contact our experts

Talk to us