Beginning in 2013 the new HVDC PLUS technology will transmit 2,000 megawatts (MW) as direct current over a distance of 65 kilometers underground. This system, which is being partially funded by the EU, connects the French and Spanish grids between Baixas and Santa Llogaia. At present the two countries’ grids are linked only by low-capacity lines.
Power grids will have to be substantially upgraded throughout Europe before more renewable energy can be used. The Desertec power generation project, in particular, will require high-performance electricity highways. Alternating current is commonly used for overhead lines, but it isn’t suitable for transmitting high capacities over long distances underwater or underground. In non-overhead systems, losses would be very high due to the charging and discharging of the cable capacities. In an HVDC system, on the other hand, transmission losses are 30 to 40 percent lower than in a comparable three-phase alternating current transmission line.
By 2013, developers at Siemens Energy will have constructed a system that can transmit 1,000 MW through each of two cables. The power will be transmitted at the highest voltage possible for today’s cables: +/-320 kilovolts. The new HVDC PLUS power converter stations use VSC-MMC technology, which is not only more flexible and robust than today’s systems, but also less prone to faults. At the heart of the new system is a converter that uses insulated gate bipolar transistors (IGBTs), which are semiconductor devices that convert alternating current into direct current and vice-versa. The system is very flexible since IGBTs can be switched at any time, no matter how high the voltage. A reactive power exchange is possible between each power converter and the three-phase alternating current network, which helps to stabilize overloaded grids. In addition, MMC technology causes few high-frequency faults, which diminish voltage quality. So there is no need for high frequency filters. The system also has a black start capability, which means the grid doesn’t require external assistance to gradually restart after a blackout. Another advantage of the system is that the energy converters don’t have to change their polarity if the direction of the transmission is reversed, thus reducing wear and tear.
A 1,000-MW HVDC cable was recently put into operation along a 260-kilometer underwater line between the Netherlands and the UK. HVDC systems are part of Siemens’ environmental portfolio, with which the company generated about €28 billion in sales in 2010.
Dr. Norbert Aschenbrenner | Siemens InnovationNews
Touch Displays WAY-AX and WAY-DX by WayCon
27.06.2017 | WayCon Positionsmesstechnik GmbH
Air pollution casts shadow over solar energy production
27.06.2017 | Duke University
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
27.06.2017 | Power and Electrical Engineering
27.06.2017 | Information Technology
27.06.2017 | Physics and Astronomy