Absolute reliability for onshore and offshore wind farms
Modern wind power plants produce approximately 20 times more electricity than plants 20 years ago, all with a simultaneous reduction in cost. Still, wind farms are a substantial capital outlay that demand high availability for a dependable return on investment. To ensure this, all system components must operate with extreme reliably.
For many years, Balluff has worked together with leading turbine manufacturers to develop sensors, measurement systems, and associated solutions tailored to the specific requirements of the wind energy industry, in both onshore and offshore wind farms.
To achieve maximum efficiency in wind power plants, the turbine nacelles must be oriented to the prevailing wind. Balluff's inductive proximity sensors detect the position directly at the gear ring of the azimuth adjustment and make it possible to reliably move the nacelle to the optimum position.
Balluff's robust sensors are ideally suited for inexpensively and redundantly supplementing the primary feedback from a rotary encoder. In contrast to rotary encoders, inductive proximity sensors mount simply and require special couplings.
Reliable turbine blade pitch control is essential for speed regulation, peak energy production, and safe operation. An extensive worldwide installed base is testament to the dependability of Balluff's magnetostrictive linear position cylinder sensors. These hydraulic pitch control sensors undergo rigorous in-house destructive testing during development. Analysis of test specimens reveals potential high-stress failure modes, which are subsequently designed out of the final product. Balluff's expertise in developing robust linear position sensors has lead turbine manufacturers the world over to trust Balluff as the preferred hydraulic pitch control sensor supplier.
Imbalances and wind loads shorten the service life of the bearings and the drive train of wind turbines. Balluff's distance-reading analog inductive proximity sensors monitor variation in the spaces between components in critical locations. When excessive stresses are detected, corrective action can be taken to reduce loads and prevent premature wear and damage that would otherwise shorten equipment life.
Balluff's rugged inductive proximity sensors report the rotor speed of wind turbines. Two inductive sensors monitor the movement of the holes in the locking plate, thus measuring the rotational speed and detecting the direction of rotation of the rotor.
Balluff's magnetic encoder systems can report the speed of wind turbine rotors with extreme accuracy, even at low speeds. The magnetic tape measurement system is simply wrapped around and attached to the main shaft. The system communicates standard quadrature incremental encoder signals that are compatible with many control systems. The encoder system can determine the direction of rotation and can also provide position feedback to determine the correct position to engage the rotor lock for service.
The encoder system operates without mechanical contact between the reader head and coded track. The generous reading distance of the system tolerates real-world variability in concentricity about the rotational axis, increasing installation flexibility and reducing costs.
Regulating generator or alternator shaft speed is critical to controlling the power quality being fed into the grid. Balluff's magnetic ring encoder operates without mechanical contact between the reader head and coded ring. The generous reading distance of the system tolerates real-world variability in concentricity about the rotational axis, increasing installation flexibility and reducing costs.
During maintenance procedures, for personnel and equipment safety, the wind turbine shaft must remain at a standstill with the rotor blades feathered out of the wind. Balluff's hydraulic pressure-rated inductive sensors report the extended/retracted end-of-stroke position of rotor locking cylinders and pitch control cylinders.
Strong gusts of wind and sustained high winds during storms can exert strong forces on the tower of a wind turbine. Balluff's inclination sensors offer non-contact angle measurement to indicate the deflection from vertical and the corresponding amount of stress on the tower structure.
Disk brakes are used at various locations in wind turbines. Balluff's distance-reading analog inductive proximity sensors directly monitor disk wear at the braking surfaces. They also monitor brake pad wear by reporting the excursion of the metallic backing plate during braking operations. The data reported by these analog sensors can be monitored continuously and used for scheduling preventive maintenance at the appropriate time, neither too early nor too late.
Optimum fill levels should always be maintained in the expansion tanks gearboxes, hydraulic systems, and cooling systems. Balluff's capacitive level sensors detect the maximum and minimum fill levels without direct contact to the media, either through the container wall or with the help of mounting adapters. They can also be installed in the oil pan as a leak sensor and will reliably report the presence of oil where it shouldn't be.