Turbine OEMs are constantly looking for ways to improve on existing models. Siemens’ recent SWT-3.3-130, with a 3.3 MW nominal power rating and 130-m rotor diameter, does just that. Ideal for medium to low-wind environments, the turbine is the newest addition to Siemens’ D3 platform (D for direct-drive technology and 3 for the predominant megawatt power rating).
Featuring 63-m long, fiberglass-reinforced epoxy blades, the SWT-3.3-130 delivers up to 19% more energy output compared to its predecessors—SWT-3.0-113 and SWT-3.2-113—according to Siemens. “Thanks to the blades’ aeroelastic design, they are much lighter, helping to lower the cost of the energy,” the company said. Mounted on pitch bearings, the blades can be feathered 80° for shutdowns. “While new servomotors ensure precise rotation of the nacelle even at high wind pressures, particularly strong hydraulic cylinders in the newly designed rotor hub enable exact adjustment of rotor-blade angles,” Siemens said in a recent press release. Additionally, the lighter blades limit the static loading of the nacelle and tower.
A redesigned cooling system in the nacelle ensures optimum cooling for the synchronous, PMG generator. The generator connects with a flange to the nodular cast-iron rotor hub, which has also been upgraded from previous models to provide a simpler and more comfortable work environment for technicians.
Tower heights for the SWT-3.3-130 range from 85 to 135 m. The tower, equipped with platforms and electric lighting, features internal ascent and direct access to the nacelle and yaw system, making it easy for technicians to access. Mounted upwind of the tower, on a horizontal axis, sits the 130-m, three-bladed cantilevered rotor. Its variable speeds keep noise to what the company deems “an acceptable level.” To stabilize the grid, Siemens said it included “reactive power at no wind” and “inertia response” features.
A microprocessor-based industrial controller governs turbine operations with switchgear and protection devices. The company said its WebWPS SCADA system “offers remote control and a variety of status views and useful reports from a standard Internet browser.” Siemens’ TCM condition monitoring system also comes with the turbine.
With a 13,300 m² swept area, 3 to 5 m/sec cut-in wind speed and an annual output of 16 GWh (when operating at 8.5 m/sec), it’s easy to see how the SWT-3.3-130 exceeds annual output of its predecessors by about 17 to 20%. Siemens plans to have the new turbine available by early 2017.
By the numbers
Nominal Power: 3.3 MW
Rotor Diameter: 130 m
Swept Area: 13,300 m²
Rotor Speed Range: 12.2 rpm
Rotor Tilt: 7.5°
Blade Length: 63 m
Nominal Voltage: 690 V
Nominal Frequency: 50 or 60 Hz
Hub Height: 85, 110, 120 or 135 m
Cut-in Speed: 3 to 5 m/sec
Cut-out Speed: 30 m/sec
Filed Under: News, Turbines