Wind power

Reliable and cost-effective solution for higher wind power plant efficiency

The solution

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.

The features

• Rugged, fully-potted electronics
• Shock- and vibration-resistant
• Non-contact and wear-free for long service life
• Suitable for wide temperature and humidity fluctuations
• Corrosion-resistant stainless steel housings

High-reliability position feedback for pitch control cylinders

The solution

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.

The features

• Non-contact, wear-free operation for long service life
• Pressure-rated to 600 bar
• Developed to withstand high levels of shock, vibration, and thermal stress

Longer service life thanks to reduction of imbalances and wind loads

The solution

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.

The features

• Non-contact and wear-free for long service life
• Compact designs for easy integration

Protect wind turbines against overspeed

The solution

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.

The features

• Rugged, fully-potted electronics immune to contamination
• Shock- and vibration-resistant
• Non-contact and wear-free for long service life
• Suitable for wide temperature and humidity fluctuations
• Extended low temperature range to -40° C

Extremely accurate measurement of rotor speed, rotational direction, and determination of rotor lock position

The solution

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.

The features

• Adaptable to a wide range of shaft diameters, including very large shaft sizes
• Simple, space-saving installation
• Non-contact, wear-free operation for long service life
• Extremely accurate, even at very low speeds

Maintain precise shaft speed regulation

The solution

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.

The features

• Systems available for a wide range of shaft diameters, including very large shaft sizes
• Simple, space-saving installation
• Non-contact, wear-free operation for long service life
• High counts per revolution for precise speed regulation

Reliable confirmation of rotor lock and pitch cylinder status

The solution

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.

The features

• Pressure rated to 500 bar
• Installed directly into the pressurized areas of hydraulic cylinders to monitor piston position
• Stainless steel housings resist corrosion
• Analog version for soft stop upon reaching end-of-stroke

Angle sensors report excessive tower deflection during high wind conditions

The solution

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.

The features

• Detects the change in angle with respect to the horizontal
• High accuracy over a measurement range up to 360° (one rotation)
• Compact, robust metal housing enables simple installation
• Absolute measuring signal: correct position reported upon power up

Simple maintenance and longer service life thanks to automatic monitoring

The solution

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.

The features

• Absolute, continuous distance measurement to metallic targets
• Non-contact and wear-free for long service life
• Wide selection of analog measuring ranges
• Compact designs for easy integration

Maintain reliability for your gearbox, hydraulic systems, and cooling systems

The solution

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.

The features

• Rigorous destructive testing and design ensures reliability
• Non-contact level detection through plastic container walls
• Versions to detect oil- or water-based fluids