Power exchange to become more economical

May 13, 2013
Power exchange to become more economical
Power electronic modules of Siemens multilevel direct converters, being used in Häggvik in the greater Stockholm area in Sweden: The Sitras SFC plus systems use state-of-the-art multilevel power converter technology, which makes it possible for them to convert energy highly efficiently and with almost no system perturbations. In addition, they are quieter than conventional systems and have a smaller footprint. To strengthen the traction power supply networks by establishing additional links to the public power supply grid, Siemens will supply more converters of this type to Sweden and to Switzerland.

Siemens is facilitating the efficient flow of energy between the power network of an electric railway system and the public power grid. The company is delivering 11 gateway power converters to Sweden, Austria and Switzerland. In these countries, and many others, the rail system operates its own power plants and a private electrical grid that is connected to the public grid at certain points. As the amount of renewable energy increases, these connection points are becoming more important. For example, the rail system in Sweden has plans for eight new converters that will provide access to hydroelectric power from the public grid beginning in mid 2015. In Austria, a new converter will allow the rail system to feed excess electricity generated by its own hydroelectric plants to the public power grid more efficiently starting in 2014. The new converter will also connect the planned Tauernmoos hydroelectric plant with the railway system grid. Altogether, including two converters for Switzerland, these contracts are worth a total of €68 million.

Power converters change the frequency and voltage of electricity in one system so that it can be fed into another system. They are necessary because in the countries already mentioned, as well as in Germany, the railway system grid uses a frequency of 16.7 Hz, whereas the public grid operates at a frequency of 50 Hz.

The direct converters, contracted from Siemens, are from the Sitras SFC plus series. These use a modular construction of multiple power transistor components (IGBT) and capacitors connected in series to reach the desired voltage incrementally. This modern, multilevel technology loses less power during conversion compared to the previous standard solution. In addition, these units are clean. In other words they generate harmonic-free power and voltage conversions, so additional filters are not required. Multilevel installations are quieter and more compact then traditional converters and are therefore more suitable for urban areas. In Germany, Sitras SFC converters are already connecting the railway system grid with the Franken 1 power plant in Nuremberg-Gebersdorf. Nationwide, four more units will be installed in the German railway system grid in the next two years.

Siemens is also introducing this efficient multilevel conversion technology to high-voltage direct-current transmission applications. For example, it can be used to connect wind farms to the public . Technologies for the efficient transmission and transformation of electricity are part Siemens' Environmental Portfolio, which earned the company sales of around €33 billion during the last fiscal year.

Explore further: Cook farm waste into energy

add to favorites email to friend print save as pdf

Related Stories

Power storage buffers fluctuating solar power

May 11, 2012

Siemens has developed an energy-storage system that can act as a buffer in electrical power grids. The aim is to provide a buffer against short-term fluctuations in output from renewable energy sources. Such ...

Smart software for self-regulating smart grid

May 24, 2011

Siemens and the utility company Allgauer Uberlandwerk (AUW) in the city of Kempten, Germany, are testing the smart grids of the future. The tests focus on optimized power distribution and the use of a self-organizing ...

Grid stability thanks to precise forecasts

Jun 11, 2012

A self-learning software system from Siemens can stabilize power grids. The program, which is based on neural networks, can forecast the electrical output of renewable energy sources over a 72-hour period ...

A world record in direct current transmission

May 03, 2011

Siemens is building power converter stations for a high-voltage direct current (HVDC) transmission system with a record capacity of 2 x 1,000 megawatts. Beginning in 2013 the new HVDC PLUS technology will ...

Recommended for you

Website shines light on renewable energy resources

11 hours ago

A team from the University of Arizona and eight southwestern electric utility companies have built a pioneering web portal that provides insight into renewable energy sources and how they contribute to the ...

Better software cuts computer energy use

11 hours ago

An EU research project is developing tools to help software engineers create energy-efficient code, which could reduce electricity consumption at data centres by up to 50% and improve battery life in smart ...

Cook farm waste into energy

Dec 17, 2014

It takes some cooking, but turning farm waste into biofuels is now possible and makes economic sense, according to preliminary research from the University of Guelph.

Developing a reliable wind 'super grid' for Europe

Dec 17, 2014

EU researchers are involved in the development of a pan-European 'super grid' capable of dispersing wind power across Member States. This will bring more renewable energy into homes and businesses, help reduce ...

Boeing 737 factory to move to clean energy

Dec 16, 2014

Boeing said Tuesday it plans to buy renewable energy credits to replace fossil-fuel power at the factory in Washington state where it assembles its 737 commercial airplanes.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.