SIEMENS

• Text Size
• Share
• Print this page

When combined with steam turbines, gas turbines are the greenest fossil-fuel-based power generation systems. Because combined-cycle power plants can be quickly ramped up to supply electricity in a flexible manner, they ideally supplement renewable sources of energy. Boasting an efficiency of 60.75 percent in combined-cycle operation, Siemens’ largest gas turbine is a record breaker. The turbine’s output of 578 megawatts would cover the electricity needs of all of the households in Berlin. Although the turbine weighs as much as a fully fueled Airbus A380 jet, its parts operate with clockwork precision. Some 750 researchers, engineers, and skilled workers from all over the world required over ten years to develop the turbine. Corporate Technology (CT) contributed extensively to the project.

Research. CT’s ceramics experts have conducted research into new, robust materials that can be used in the heat-insulation layers on turbine blades. They have used specialized testing methods and simulations to analyze the behavior of different materials in the turbine’s hot gases and to determine the system’s permissible load limits. This has enabled partners in the Energy Sector to increase the gas turbines’ operating temperature by about 150 degrees Celsius and its efficiency by around 1.5 percentage points. At the same time, by developing neural networks and forecasting models, CT experts in machine learning have helped to reduce emissions of nitrogen oxides and carbon monoxide. This makes the turbines more environmentally friendly and cuts the cost of scrubbing exhaust gases.

Development. Using a model-based design approach, CT has conducted a variety of simulations and implemented optimization measures to improve the development of gas turbines. Algorithms were employed to optimize the aerodynamics of the turbine blades. CT has conducted thermo-acoustic simulations of pressure fluctuations to reduce the mechanical strain caused by combustion instabilities in the combustion chambers. What’s more, using simulations for studying the service life of turbine blades, it has been possible to make the blades more robust. Along with other experts, sensor specialists from CT also continuously monitor the interior temperature of gas turbines and measure nitrogen oxide emissions. This has to be done if the turbines are to be run under optimal operating conditions. By visually measuring exhaust gas temperatures, specialists support the gas turbine retrofitting business. Before a turbine’s efficiency can be boosted through a variety of optimization measures, experts have to make sure that no part of the system will overheat.

Manufacturing. CT experts have played an important role in the development of a welding technique that saves time and material through automation, while also improving the quality of welded joints. Their laser welding expertise could also prove useful when it comes to repairing turbine blades. In addition, another technique could make it easier to reuse blades. Here, all deposits have to be removed before a turbine blade can be restored. Highly concentrated hydrochloric acid is currently used to do this. However, it is easier and less expensive to use an electrochemical technique for which CT owns the patents. What’s more, this method can be performed in a more controlled manner and reduces the risk of damage to the blades during the decoating process.

Testing. Together with partners at the Energy Sector, experts from CT have developed a platform for the non-destructive testing of turbine blades. During various inspections, the blades’ condition is evaluated over their entire life cycles. The resulting statistical data can flow into the system’s future design and be used to help optimize the existing concept. Production experts also use this system to inspect delivered blades. Energy’s service teams can also keep an eye on the gas turbines during operation. To monitor the system in real time, CT researchers have developed a powerful tool called Seneca, which evaluates the data recorded in the gas turbines by thousands of sensors. In addition to pressure, these sensors monitor temperature, vibrations, and many other factors. Each second, Seneca transmits about 5,000 values from each gas turbine to 100 computer centers around the world. The online system compares 500 to 1,000 behavioral models with one another and displays any deviations from the norm as a graph.

• Text Size
• Share
• Print this page

Robust, wear-free, low-maintenance turbines provide offshore wind power plants with a crucial competitive edge. Siemens offers gearless wind turbines. Instead of complex mechanical systems, such turbines have a generator with a permanent magnet that converts motion directly into electricity. Corporate Technology (CT) made important contributions to the development of the first gearless 3.1-megawatt wind turbine. For example, CT experts conducted 2D and 3D simulations during the generator’s design phase and created a digital prototype. This enabled a cross-sector team to minimize the air gap between the stator and the generator’s rotating part, leading to less power loss while ensuring maximum stability. In cooperation with experts at the company’s operating units, CT used other 3D models to design the cooling system and integrate it into the generator. To ensure manufacturing would be as cost-efficient as possible, specialists at CT also developed an assembly design for mounting and insulating the magnets in a manner suited to series production. These measures halved the generator’s manufacturing costs and reduced the 3.1-MW turbine’s weight from 73 tons to about 50 tons. Together with the nacelle and the rotor, the Siemens 6-MW-system weighs around 350 tons overall, making it the lightest turbine of its kind on the market. CT production experts created a modular factory concept in accordance with the principles of the Siemens Production System for the final assembly of the generator. Production is very flexible and optimized in such a way that manufacturing times have been halved to less than 850 hours, compared to the prototype. CT also tested the generator’s cooling system to ensure that it worked properly before series production commenced.

• Text Size
• Share
• Print this page

In conjunction with their sister systems — LEDs — organic light-emitting diodes, or OLEDs (pictured above), will serve as the main source of artificial light in the future. OLEDs consist of extremely thin plastic films that light up when electricity flows through them. At the end of 2009, Siemens subsidiary Osram launched Orbeos — the first commercial OLED light tile. From the very start, Corporate Technology (CT) was involved in all stages of the new technology’s research, development, production, and testing. The first prototypes were created more than 15 years ago in Germany in an Erlangen clean room lab, which continues to produce small batches of OLEDs and subsequently tests their quality. Experts at CT developed the first OLED components and production processes — particularly those used to synthesize and work the plastic. Researchers also worked on creating flexible OLEDs and ways of efficiently encapsulating the air- and humidity-sensitive systems. More recently, they have been striving to develop dopants that reduce material costs and therefore make OLEDs more competitive. In 2011 Osram announced that it had created an OLED whose levels of efficiency set new records. To this end, Osram used an inexpensive dopant from CT. In another project, experts from CT are currently researching special substances that could help to improve charge transfer.

• Text Size
• Share
• Print this page

Over the past four years, the eCar lighthouse project at Corporate Technology (CT) has been making major contributions to the advancement of electric mobility. The most recent development is a hybrid-electric aircraft that completed its virgin flight in summer 2011. Essentially a glider, this aircraft is powered by a Siemens electric motor. The battery is charged by a small combustion engine that always operates at an optimal level, thus cutting the plane’s fuel consumption and emissions by around 25 percent compared to what it otherwise would be.

Research. In cooperation with the automaker Ruf, experts at CT have built electric sports cars on the basis of a Porsche 911. Using a unique test rig, experts can analyze and improve the behavior of the motors under conditions relevant to real-life use. This spring (2012), specialists installed two high-performance, high-torque wheel hub motors into a Roding sports car for the first time. These “smart wheels,” which function as a drive system and brakes, contain a motor, power electronics, and a control system. The use of an additional brake circuit enhances safety. The two motors enable the system to drive each wheel separately. Researchers are also developing a new communications architecture for automobiles. New infotainment and driver assistance functions are only to be installed as software, irrespective of the hardware used. Together with BMW, CT researchers have developed a system that uses magnetic induction to charge a BMW ActiveE through a plate on the ground, without any direct vehicle contact. Such wireless charging is almost as efficient as charging with the help of cables, besides being more convenient. In other words, it could increase people’s acceptance of electric vehicles.

Development. To ensure inductive charging can be easily performed, the system must help drivers put their vehicle into the right position and “know” when the charging process can begin. To make this possible, CT experts have developed a large number of wireless transmission components that perform several tasks. For example, they “wake up” the charging system; fine-position the vehicle; transmit data; and monitor the air gap, which is several centimeters wide, during the charging process. CT researchers have also developed an extremely high power-density power train. Consisting of a converter, a motor, and a control system, it has been installed into a variety of vehicles. During acceleration, the prototype motor generates 125 kilowatts for 30 seconds and produces a maximum torque of 230 newtonmeters. The motor has a continuous output of 60 kilowatts. To design the system, the researchers used tools to simulate the complex interactions between the associated electromagnetic fields, thermodynamic processes, and mechanical structural strength. The power electronics used to drive the vehicle are also employed to charge it. Specialists are also using new concepts to triple the electric motors’ power density, while energy experts are developing charging hardware. So far they have improved the converters’ efficiency and simplified the production of the power electronics. In addition, energy storage experts have developed a simulation model that predicts the operating performance of lithium-ion batteries. In addition to enabling users to determine their battery’s potential performance at any time, the model also depicts the battery’s thermal behavior in a variety of scenarios. CT researchers are also developing new materials for magnets that require little or no rare earth elements. Moreover, they intend to use recycling technologies to salvage these valuable materials. CT’s PLM experts are optimizing manufacturing processes so that electric motors can meet the demands of the automotive industry.

Manufacturing. The biggest cost factor in electric cars is the battery. The only way this cost can be significantly cut is to improve power density and mass-produce the batteries. Siemens offers battery producers its expertise in industrial automation. Researchers at CT can offer extensive expertise and knowledge of the process automation that is needed to manufacture such batteries. In addition to coming up with an appropriate automation concept, they have also created a quality and process control system. Among other things, this process involves applying pastes in very thin and nearly homogenous layers with minimal tolerance. This procedure has to be separately optimized for each manufacturer.

Testing. Experts at CT are running a number of projects to determine how people use and assess electric vehicles under everyday conditions. To this end, they also manage Siemens’ own test fleet. In fall 2010, the company loaned 20 small electric cars to employees, who have been testing the vehicles. Since fall 2011, Siemens has also operated a car-sharing fleet in Berlin to study how well electric vehicles are accepted by drivers and other issues.