Wind turbine systems can be operated in all climatic zones and regions as well as out at sea. Tidal power stations can also operate below the surface of the ocean: Both the tidal difference between low and high tides as well as the kinetic energy of the tidal currents can be converted into electricity. However, the energy recovery process must always have the highest efficiency, be cost-effective and reliable -– even when the wind force or solar radiation fluctuate. With its innovative systems and environmentally friendly technologies, Siemens – one of the world‘s leading suppliers in this area – has a perfectly coordinated portfolio to address the widest range of applications.

Systems for efficient wind turbines

Systems from Siemens stand for a maximum energy yield but with minimum operating costs. Our comprehensive portfolio offers perfect generator systems with outstanding power and performance for every wind turbine type: Up to over 5 MW forboth onshore and offshore applications. A high percentage of these are manufactured by Loher, a Siemens daughter company. For reasons of economy, double-fed slipring generators are predominantly used. What makes them different from conventional induction generators is the fact that significantly smaller frequency converters can be used. The reason for this is that they do not have to be dimensioned for the full power rating of the system.
Additional advantages: Bearings can be changed in the gondola, a brush slip ring combination that has been optimized to achieve the longest lifetime and higher energy yield using an optimized efficiency characteristic with increased power factor. All of this is supplemented by a special paint system to provide optimum corrosion protection under extreme environmental conditions. The variable-speed operation allows the windturbine to be perfectly adapted to the prevailing wind conditions. The power is generated, decoupled from the line frequency so that the wind turbine can also be operated at the optimum efficiency at different speeds. The wind turbine converters, utilizing state-of-the-art IGBT technology, can handle all control types that are typical for wind turbine systems and fulfill the highest requirement when it comes to electrical line supply compatibility. All of these points ensure economic system operation that is truly fit for the future.

Gearless offshore alternative

Especially in the offshore area, wind turbine systems must be especially rugged and reliable. To achieve this objective, we are also testing a gearless ring generator that uses permanent-magnet technology as alternative to our well-proven solutions. This solution has ratings that extend up into the multi-megawatt class. Gearless ring generators are almost maintenance-free and are therefore ideal for offshore applications where maintenance and repairs involve the use of either a boat or a helicopter. This makes them correspondingly time-consuming, expensive and also dependent on the weather. The permanent-magnet synchronous generators used in the gearless systems have significantly lower losses when compared to the electrically excited variant. Not only this, their envelope dimensions and weight are approximately one quarter less. This simplifies transport and installation. Electrical excitation is not required, thus eliminating wearing parts that are prone to failure and require intensive maintenance.

Tamed water power: solutions for highavailability tidal power stations

Different than conventional tidal powerstations, modern systems do not require a dam that can have a negative impact on the landscape. For these types of tidal power stations, generator systems from Loher from the area of subsea drive technologyare used. They have proven themselves many times over in water depthsdown to 1000 m. These generators are integrated in a turbine that operates down to depths of 70 m on the seabed for 20 years without requiring any service or maintenance. Pilot projects that have generator ratings of 1 MW per turbineand a torque of 600 kNm have already been planned. The permanent-magnet synchronous generators have a high efficiency and are absolutely rugged, reliableand quiet – to ensure that the ocean faunais not disturbed. Not only this, they distinguish themselves as a result of the highest degree of availability and energy efficiency as they are completely maintenance-free. They are cooled just by the seawater and are protected against corrosion.