Technical description
Wind turbines are rotating machines that convert kinetic energy from wind into mechanical energy which is then converted into electricity.
Turbines used in wind farms for commercial production of electrical energy have three blades and servo motors that keep them steered in the wind direction. The blades have high point speeds – up to six times the wind speed – and are extremely efficient, with a low torque ripple that helps ensure good overall reliability. The blades, with a length of between 20~40 m or more, can be controlled by the Tiger 50/600, Elmo's high-quality digital servo control unit. Elmo's Eagle 35/200 – a compact, powerful and intelligent servo drive – is used as a backup drive for system control in the event of an emergency or malfunction.
The blades rotate at 10~22 revolutions per minute, although more advanced models rotate at a constant speed. In this system solution, servo drives control the blades in such a way that they continuously change their angle in the air flow, so that a constant speed is maintained. All turbines are equipped with safety shutdowns to prevent damage at high wind speeds.
The challenge:
When designing an application system based on Elmo's products for a wind turbine, we face the following challenges:
- The need for precise control at high speed of the three blades of the wind turbine.
- The ability to control the blades driven by brushless DC motors.
- The requirement for high system reliability under extreme and variable conditions.
- The need for a system based on products that meet security requirements and have redundancy/backup options.
- The requirement to design a compact system that requires minimal space.
- The possibility of advanced programming capabilities in the drive to respond to unexpected situations.
- The need for a powerful, cost-effective and intelligent motion control system.
- The requirement for support of an absolute pulse generator.
- The possibility of direct connection to the three-phase network without the need for a DC power supply.
Elmo's system solution
The limited space in the wind turbine for the installation of servo drives requires compact electronics with very powerful motors to deliver the required high torque and precisely control the speed of the blades. The Tiger and Eagle drives are designed for high power density and top performance, where safety is an essential requirement.
The Tiger digital drive was selected as the primary drive due to its compact size, high power and ability to support a max. 600 VDC bus. It is a fully digital servo drive that can supply the up to 50 A continuous current required for the high torque to drive the blades at high speeds.
Technical description:
The practical application is based on proven, ready-to-use products, where the system controls TIG 50/600 and EAG 35/200 are used as primary and auxiliary systems respectively. They are designed for high-performance servo systems typically used in high-power military applications. The drives are MIL-STD compliant and can operate in extreme environmental conditions (EEC). The Tiger is powered directly from the three-phase network without the need for a separate DC power supply due to the internal integrated DC power supply. The Eagle serves as an additional backup that further increases the reliability of the system. The TIG 50/600 and EAG 35/200 are extremely reliable products that are integrated into many military systems. The reliability of the drive is not inferior to that of the brushless DC motor of the wind turbine.
For more information: info@eltrex-motion.com
Nederlands