Efficient energy transformation with HVDC Reliable electrical power supply is based upon highly developed power grids. That is why Siemens is right there wherever networks are being expanded, retrofitted, or newly built. As a world-leading manufacturer, systems integrator, and provider of complete solutions and services, Siemens enables power utilities to transport and distribute electricity reliably and economically from the power plant to the customer. Our comprehensive product range covers transformers for power stations, substations, and HVDC converter stations as well as transformers for industry and transportation, reactors, and accessories. For more than 100 years, Siemens transformers have been synonymous with top quality – as a result of ideas, knowhow, and unequalled experience. All over the world, Siemens stands for highest quality and reliability in development, production, and installation as well as in commissioning and maintenance. HVDC remote energy transmission – long distance with low losses HVDC remote transmission makes it possible to transport electrical energy over long distances. The conversion of alternating current into direct current allows for transmission with comparatively low losses and for the interconnection of grids of different frequencies. Siemens is known for having developed unique new controls and instrumentation for HVDC transmission systems, and our transformers and smooth reactors have proven their outstanding performance for decades. World-leading competence – always right at your doorstep As an internationally networked provider with a strong local presence and a tight sales and service network, we are always on the spot – where- and whenever you need us to master a challenge successfully. Because for us, being a dependable, long-term partner for our customers is just another aspect of the reliability Siemens is noted for. The importance of HVDC applications With the rising energy price, power exchange between large grids will become more and more common. For example, an area (A) with abundant hydro power in a cold region may rely on another area’s (B) coal-fired energy in winter since the frozen river cannot produce power. While in the rest of the year, the region B may rely on region A’s hydro power to meet the peak demand in summer. New HVDC applications are seen between existing, wellestablished networks. A back-to-back link can easily combine two different AC networks together, even with different frequencies. Both network users are able to take advantage of balanced load / output due to different time zones or different living behaviors that are causing delaysin peak load. Such solutions can also help customers to strengthen and optimize their networks.
The changing environment provides more and more opportunities to HVDC solutions, and Siemens is prepared to provide its customers with either our solution or with converter transformers as a loose component. 800 kV UHVDC converter transformers for China In 2007 Siemens contracted the first two Chinese 800 kV DC projects: Yunnan–Guangdong at 5,000 MW and Xiangjiaba–Shanghai at 6,400 MW. Both projects are featured of long-distance transmission with large-capacity electric power. With increasing demand of power in coastal areas of China, the hydro power in the western area is an ideal solution with low impact to the environment. However, the challenge lies in the transmission of bulk power over ultra-long distances.
The Siemens solution helped the customers to solve this problem. China Southern Grid awarded the 800 kV transformer contract of both terminals to Siemens in summer 2007, which is the world’s first order of this voltage level. Furthermore, Siemens is committed to help the local suppliers to build the low end transformers in China. At the end of 2007, China State Grid also awarded their first order of 800 kV DC transformers to Siemens, which shows the great confidence in Siemens technology of two majorutility groups of China.
