System solution for yaw systems

Distributed servo drive technology in the nacelle adjustment optimizes yaw systems

If the wind direction changes, the yaw system rotates the wind turbine rotor optimally into the wind. Apart from the electric drives, hydraulic brake systems are typically also used for this horizontal alignment and locking of the nacelle. However, the permanent use of the brake unit in the active wind tracking results in constant wear in the yaw system, leading to high maintenance expenditure. The use of the existing electric drive systems to develop the required counter-torque and to clamp the mechanism results in less wear and is more efficient.

Traditional drive systems are often based on mains-operated asynchronous motors without soft start, as these are relatively inexpensive. To achieve a safe starting torque in soft supply networks despite that, the motor and the upstream power supply elements are often greatly oversized. However, modern wind turbines offer less and less space for control cabinets. Additional weight and volume must be avoided in particular in the nacelle. These requirements are fulfilled by the AMP8000 drive system with decentralized servo functionality integrated in the motor. Depending on the turbine size and load requirement, the quantity and output of the motors can be adapted for the reliable dimensioning of the drive and braking torques. In comparison with traditional solutions, the servo drive system based on the AMP modules from Beckhoff offers greater efficiency and the safety of adequate breakaway torques even in the case of grid fluctuations.

On account of the wear-prone braking systems, the wind tracking is operated only very sparsely in many turbines. With the new approach, in which the dynamic braking power is achieved without the assistance of the hydraulic brake system, a higher energy yield can be achieved at many wind farm locations through more dynamic wind tracking.

Your advantages at a glance:

  • increased energy yield through more dynamic wind tracking
  • cost reduction through lower maintenance requirement
  • AMP modules reduce installation space and weight in the nacelle
  • minimization of the cabling and assembly costs
  • optional safety functions, e.g. for system maintenance
  • integrated condition monitoring and remote diagnostics

Beckhoff technology highlights for yaw systems

The PC-based control technology enables a high-performance control of the drive system

The PC-based control technology enables a high-performance control of the drive system. This allows the dynamic wind tracking and the necessary system damping to be flexibly designed. The modular azimuth software can run on a dedicated small controller or – more cost-effectively – directly on the wind turbine control system. The system is scalable in terms of the drive and braking power and the number of axes is freely selectable. To distribute the load torques symmetrically and to simultaneously brace the mechanism to dampen the system, the multi-axis system works with a dynamic torque regulation. This allows the gear backlash on the axes to be compensated in a simple way and to achieve a longer service life. The key here is to connect both the speed and position controller as well as the torque controller on the central CPU.

Beckhoff product highlights for yaw systems

AMP800 servo drive system: the system solution for yaw systems
AMP800 servo drive system: the system solution for yaw systems

The modular AMP8000 servo drive system is qualified for direct assembly in the nacelle

By relocating the drive electronics into the servomotor, the space required for the azimuth system in the nacelle is reduced considerably. Via a power supply module, up to five drives work efficiently together in a DC link group. The servo drives contain all of the sensor technology for the cascaded position control and a maintenance-free permanent magnet holding brake. The absolute feedback system, the holding brake and the power electronics are connected by hybrid cables (One Cable Technology – OCT). This saves material, space and installation work.

Furthermore, the AMP8000 drives include a TwinSAFE logic for the configuration of drive-integrated safety functions. The STO/SS1 functions are available as standard. For the connection of secure and purely functional I/Os in IP65, the AMP power supply module provides EtherCAT P interfaces. No further external components such as 24 V power supply units are necessary. Based on AMP8000, the azimuth system can be integrated in the nacelle modularly and economically without control cabinets.