Today, the increasing energy demand and the need for clean power generation leads everyone's mind to the concept of renewable energy sources. With highly efficient, solid and reliable wind turbine Siemens Wind Power offers a solution to meet energy needs and environmental awareness.
Experience from more than 9,800 installed wind turbines
Since 1980, the focus was on developing competitive wind turbines. From the first 22-kW wind turbine up to the MW range turbines of today, the products have helped harnessing the power of wind.
Secure development requires specialist knowledge, and no other wind turbine manufacturer can match the specialist knowledge of Siemens Wind Power. Based on more than 30 years of continous presence in the wind industry, we offer the best-skilled management and engineering staff and the designs of any new product combine the accumulated experience of all the previous turbines with the latest advances in the fields of aerodynamics, structural dynamics, noise reduction and grid performance. The result is a reputation for high quality, logical and solid design and creative details that was founded with the first 22-kW turbines of 1980 and has continuously been increased since then. A reputation that is well deserved by the MW range "workhorses" of today.
The most important resource of Siemens Wind Power is undoubtedly the more than 7,800 employees - their experience, technical know-how and enthusiasm. An experienced management team vouches for continuity and confidence. We offer a unique mix of experience and innovation, wisdom and vision. A mix that makes Siemens Wind Power a reliable supplier and a dependable partner.
The large-scale wind farms developed in recent years require significant project management know-how in order to be completed successfully. Siemens has extensive experience in this field and has, by the timely completion of hundreds of wind farms, including the challenging offshore wind farms, proven itself as a competent supplier of large, complicated projects.
Within the last 25 years, our engineers have developed and improved state-of-the-art wind turbines with superior performance and reliability.
The Siemens IntegralBlades® - a key technology unique in the industry
All blades used for the SWT-1.3-62 and onwards are fitted with Siemens blades manufactured with our patented IntegralBlade® technology. The blades are made of fiberglass-reinforced epoxy resin and their external design represents state-of-the-art wind turbine aerodynamics.
Invented by Siemens Wind Power, the IntegralBlade® technology manufactures wind turbine blades in one piece using a closed process. The glass fiber reinforcement is laid out to dry using a special molding arrangement with a closed outer mold and an expanding inner mold. After completion of the lamination of the glass fiber, the epoxy resin is injected under a vacuum. Following this injection, the blade is hardened at a high temperature while still enclosed in the mold. Once the blade is hardened, it is removed from the outer mold, and the inner mold is collapsed with a vacuum and pulled from the blade. The result is a complete, seamless blade finished in one process. A truly integrated success.
Compared with the traditional processes used by other blade manufacturers, the IntegralBlade® process has several advantages. The process is efficient in manpower and space, requiring only one mold set for the manufacturing cycle. Additionally, there are no issues relating to tolerances between shells and spars. The resulting blade is an integrated structure with no glued joints that act as weak points potentially exposing the structure to cracking, water ingress and lightning.
Since the IntegralBlade® manufacturing process is closed-in, the blade factory offers a clean and attractive work environment. The resins applied to the blade do not release VOCs and the risk of exposure to allergenic compounds is minimal.
Protection from the effects of direct and nearby strikes
The lightning protection of our wind turbines aims to protect from the effects of direct and nearby strikes. Even though protection from lightning can not be wholly assured, our lightning protection system has shown very good performance in wind turbine applications all over the world.
The overall design basis refers to the international standard IEC 61400-24 Lightning Protection Level I.
The components of our wind turbines are protected in various ways:
Based on comprehensive web technologies
The Siemens WebWPS SCADA system is based on comprehensive web technologies, including XML, XSL style sheets, Microsoft Internet Information Server (IIS) and ASP. With its flexible architecture, the system is fairly easy to adapt to project-specific requirements, customized data and report formats. The web server on site generates reports and stores historical data and remote terminals can be connected via modem, routers or an Ethernet network.
Communication Network
On site, the SCADA system and the wind turbines are linked with an internal communication network using optical fiber cables (preferably single-mode). Depending on the site layout, the network is split into loops each consisting of 8 to 10 turbines.
WebWPS Software
The main component of the WebWPS software is installed on the site server.
It has three distinct parts:
Status Views
A detailed view of a specific turbine will typically present the following data:
Reports
The WebWPS SCADA system provides both standardized and customized reports. All of them can be easily exported to Excel allowing quick analysis of these reports within customer organization. Some of the "standards" include:
Comply with all currently valid grid code requirements on relevant markets
Our proprietary NetConverter® power conversion system allows generator operation at variable speed, frequency and voltage while supplying power at constant frequency and voltage to the MV transformer.
The generator is connected to the MV transformer with NetConverter® power conversion system. This system provides maximum flexibility in the turbine response to voltage and frequency requirements, fault conditions, etc. and can be adapted to meet the requirements of relevant grid codes.
The power conversion system uses a number of modular water-cooled converter units in parallel mounting for easy maintenance.
Limitation of the power output in high winds is necessary
Limitation of the power output in high winds is necessary on all wind turbines, otherwise the turbine will be overloaded.
Siemens offers two types of power limitation, stall regulation and pitch regulation. Both methods are based on the continuous adjustment of the pitch setting of the blades relative to the hub. Each blade has its own hydraulic actuator unit with position feedback, ensuring continuous stable operation.
A reliable product and a well-run service organization help to ensure that wind turbines are a good investment. In addition to their strong and reliable basic construction, all Siemens turbines are accompanied by a comprehensive guarantee. This ensures that the customers know that their turbine will provide the best possible operational reliability both during the guarantee period and beyond.
The following is a brief technical description of the main components of the SWT-3.6-120 wind turbine.
The SWT-3.6-120 rotor is a three-bladed cantilevered construction, mounted upwind of the tower. The power output is controlled by pitch regulation. The rotor speed is variable and is designed to maximize the aerodynamic efficiency.
The B58 blades are made of fiberglass-reinforced epoxy in Siemens’ proprietary IntegralBlade® manufacturing process. In this process the blades are cast in one piece to eliminate weaker areas at glue joints. The blades are mounted on pitch bearings and can be feathered 80 degrees for shutdown purposes. Each blade has its own independent pitching mechanism capable of feathering the blade under any operating condition. The blade pitch arrangement allows for optimization of the power output throughout the operating range, and the blades are feathered during standstill to minimize wind loads.
The rotor hub is cast in nodular cast iron and is fitted to the main shaft with a flange connection. The hub is sufficiently large to provide a comfortable working environment for two service technicians during maintenance of blade roots and pitch bearings from inside the structure.
The main shaft is forged in alloy steel and is hollow to facilitate the transfer of power and signals to the blade pitching system. The main shaft is supported by two self-aligning double spherical roller bearings which are shrunk onto the main shaft. The bearings are grease lubricated and the bearing seals are labyrinth seals.
The gearbox is a custom-built three-stage planetary-helical design. The first two high torque stages are of a helical planetary design. The high-speed stage is of a normal helical design and provides the offset of the high speed shaft that is needed to allow passage of power and control signals to the pitch systems.
The gearbox is shaft-mounted and the main shaft torque is transferred to the gearbox by a shrink disk connection. The gearbox is supported on the nacelle with flexible rubber bushings.
The gearbox is fitted with an oil conditioning system. All bearings are lubricated with oil fed directly from a large in-line filter and is cleaned by an off-line filter unit.
The gearbox is fitted with sensors for monitoring temperature, oil pressure and vibration levels.
The generator is a fully enclosed asynchronous generator. The generator has a squirrel-cage rotor without slip-rings. The generator rotor construction and stator winding is designed for high efficiency at partial loads. The generator is protected with thermal switches and analogue temperature measurement sensors.
The generator is fitted with a separate thermostat-controlled ventilation arrangement. Air is re-circulated internally in the generator and heat is transferred through an air-to-air heat exchanger that separates the internal environment in the generator from the ambient air.
The mechanical brake is fitted to the gearbox high-speed shaft and has two hydraulic calipers.
The yaw bearing is an internally geared ball bearing fitted with a hydraulic disc brake. Six electric planetary gear motors drive the yawing.
The SWT-3.6-120 wind turbine is mounted on a tapered tubular steel tower. The tower has internal ascent and direct access to the yaw system and nacelle. It is equipped with platforms and internal electric lighting.
The wind turbine controller is a microprocessor-based industrial controller. The controller is complete with switchgear and protection devices. It is self-diagnosing and has a key board and display for easy readout of status and for adjustment of settings.
The NetConverter® power conversion system allows generator operation at variable speed, frequency and voltage while supplying power at constant frequency and voltage to the MV transformer. The power conversion system is a modular arrangement for easy maintenance and is water cooled.
The SWT-3.6-120 wind turbine is equipped with the Siemens WebWPS SCADA system. This system offers remote control and a variety of status views and useful reports from a standard internet web browser. The status views present information such as electrical and mechanical data, operation and fault status, meteorological data and grid station data.
In addition to the Siemens WebWPS SCADA system, the SWT-3.6-120 wind turbine is equipped with the unique Siemens TCM condition monitoring system. This system monitors the vibration level of the main components and compares the actual vibration spectra with a set of established reference spectra. Result review, detailed analysis and reprogramming can all be carried out using a standard web browser.
The wind turbine operates automatically. It is self-starting when the wind speed reaches an average of about 3 to 5 m/s (about 10 mph). The output increases approximately linearly with the wind speed until the wind speed reaches 12 to 13 m/s (about 30 mph). At this point, the power is regulated at rated power.
If the average wind speed exceeds the maximum operational limit of 25 m/s (about 56 mph), the wind turbine is shut down by feathering the blades. When the average wind speed drops back below the restart average wind speed, the systems reset automatically.
| Type | 3-bladed, horizontal axis |
| Position | Upwind |
| Diameter | 120 m |
| Swept area | 11300 m² |
| Nominal rotor speed | 5-13 rpm |
| Power regulation | Pitch regulation with variable speed |
| Rotor tilt | 6 degrees |
| Type | B58 |
| Blade length | 58.5 m |
| Root chord | 4.2 m |
| Aerodynamic profile | NACA63.xxx, FFAxxx |
| Material | GRE |
| Surface gloss | Semi-mat, < 30 / ISO2813 |
| Surface colour | Light grey, RAL 7035 |
| Type | Full span pitching |
| Activation | Active, hydraulic |
| Hub | Nodular cast iron |
| Main bearings | Spherical roller bearings |
| Main shaft | Alloy steel |
| Nacelle bed plate | Cast iron |
| Coupling hub - shaft | Flange |
| Coupling shaft – gearbox | Shrink disc |
| Gearbox type | 3-stage planetary/helical |
| Gearbox ratio | 1 : 119 |
| Gearbox lubrication | Forced lubrication |
| Oil volume | Approx. 750 l |
| Gearbox cooling | Separate oil cooler |
| Gearbox designation | PZAB 3540 |
| Gearbox manufacturer | Winergy AG |
| Coupling gear - generator | Double flexible coupling |
| Type | Hydraulic disc brake |
| Position | High speed shaft |
| Number of callipers | 2 |
| Type | Asynchronous |
| Nominal power | 3600 kW |
| Protection | IP 54 |
| Cooling | Integrated heat exchanger |
| Insulation class | F |
| Type | Totally enclosed |
| Material | Steel / Aluminium |
| Surface gloss | Semi-gloss, 30-50, ISO2813 |
| Colour | Light grey, RAL 7035 |
| Type | Active |
| Yaw bearing | Internally geared ball bearing |
| Yaw drive | Six electric gear motors |
| Yaw brake | Active friction brake |
| Type | Microprocessor |
| SCADA system | Web WPS |
| Controller designation | WTC 3 |
| Type | Cylindrical and/or tapered tubular |
| Hub height | 90 m or site-specific |
| Corrosion protection | Painted |
| Surface gloss | Semi-gloss, 30-50, ISO2813 |
| Colour | Light grey, RAL 7035 |
| Cut-in wind speed | 3-5 m/s |
| Nominal power at | 12-13 m/s |
| Cut-out wind speed | 25 m/s |
| Maximum 3 s gust | 70 m/s (IEC version) |
| Rotor | 100,000 kg |
| Nacelle | 125,000 kg |
| Tower for 90 m hub height | Site-specific |

Nacelle Arrangement
| 1 Spinner | 10 Brake disc |
| 2 Spinner bracket | 11 Coupling |
| 3 Blade | 12 Generator |
| 4 Pitch bearing | 13 Yaw gear |
| 5 Rotor hub | 14 Tower |
| 6 Main bearing | 15 Yaw ring |
| 7 Main shaft | 16 Oil filter |
| 8 Gearbox | 17 Generator fan |
| 9 Service crane | 18 Canopy |