Atos offers valves for easing the work of wind turbines

By Staff Report November 16, 2024 12:48 pm IST

Atos offers valves for wind turbine efficiency, precise pitch control under extreme conditions, advanced diagnostics, and seamless integration with various control systems.

The hydraulic pitch system modulates the blade’s angle in response to changing wind conditions, ensuring maximum efficiency regardless of the wind speed.

Proportional directional valves are the key component of hydraulic pitch systems, as they must ensure accurate and highdynamic control of the blade angle in the presence of high mechanical stress, typical of onshore and offshore wind turbines.

Wind turbine: hydraulic pitch system to optimise energy production from the wind

The global push towards sustainability has increased interest in alternative power sources beyond coal and fossil fuels. One of these sustainable sources is to use energy from the wind through wind turbines by converting wind movement into electrical current, possibly due to the rotor blades and a power generator. As the wind energy source is not constant, wind turbines are modulating the angle on the blades (“pitch angle”) to optimise their power generation in response to changing wind conditions. The hydraulic pitch system within the turbine hub rotates the three variable-pitch turbine blades to control the generator speed based on a feedback signal. This ensures that the electrical power required by the consumer is produced regardless of varying wind speeds, optimising the energy yield and reducing the mechanical load, thereby extending the wind turbine service life.

Electrohydraulic solutions for pitch control

A hydraulic pitch system provides an efficient and reliable way to control the pitch angle of a wind turbine. It meets requirements with long-term operative life and allows for accurate and high-performance control of the pitch angle.

With the hydraulic pitch system, the angle of the rotor blades is changed via hydraulic cylinders: the supply source is in the fixed zone of the nacelle, while the actuator of each blade rotates with the hub.

The proportional directional valves (PDV) ensure accurate and high-dynamic actuator position control. Reliability is another key factor as PDV operates in the presence of high mechanical stress: being in the rotating turbine hub, it is exposed to heavy vibrations, shocks, rotational forces, and lightning strikes. Also, PDV must be designed to operate in critical environmental conditions like northern regions or marine areas characterised by low temperatures and high humidity.

Atos proportional directional valves

Atos has developed a range of PDVs for onshore and offshore wind turbines. Atos digital proportional valves with onboard electronics offer superior performance, high reliability, and advanced tuning and diagnostic functions.

Features:

• high dynamic response with excellent spool position accuracy & repeatability
• rugged execution according to mechanical stress tests for sine/random vibrations EN 60068-2-6 and shocks EN 60068-2-27
• EMC compliance according to EN 61000-6-2, -3, -4 standards
• enhanced protection against lightning according to EN 61000-4-9 and disturbances related to medium and high voltage substations according to EN 61000-4-10
• IP66 / IP67 classification against dirt, grease and moisture
• extended ambient temperature range down to -40°C
• remote advanced diagnostic functions due to the built-in oscilloscope and permanent alarm history
• fieldbus communication CANopen, PROFIBUS, EtherCAT, POWERLINK, EtherNet/IP and PROFINET

Digital electronics enable the customisation of valve flow output and performances to match different turbine requirements, ensuring compatibility with the existing control parameters.

Atos digital proportional valves are the preferred choice for hydraulic pitch systems of several wind turbine manufacturers worldwide. These manufacturers appreciate their superior performances and reliability, the result of years of R&D and successful field experiences.