Heason sets sites on wind farms

Broadbridge Heath, UK –  - A positioning assembly from Heason Technology has been used to determine optimal sites for offshore and onshore wind farms. The product is now field proven and licensed to Natural Power, a renewable energy solutions provider based in Scotland.

ZephIR, a laser anemometer, is an easily transportable ground-based instrument combining three sealed pods for laser optics, data collection/communication electronics and battery power. ZephIR projects a conical infrared beam to illuminate particles in the atmosphere which are detected as backscattered light by an integral receiver.

Target particles along the beam produce a Doppler shift allowing the processed information to determine wind speed and direction in five pre-selected, highly accurate and repeatable distances up to 200m above the instrument. Wind speed, direction and wind turbulence information can be stored in flash memory or transferred to clients via mobile phone or satellite.

The technology is claimed to offer a significant advantage over traditional wind measurement masts, which involve the costly erection of large structures, require lengthy building permission timescales, and also elicit health and safety concerns.

Heason’s brief was to design and deliver a robust single-axis sub-micron positioning assembly for the high-speed focussing of the fibre-optic lens arrangement, which in turn determines the application-critical height accuracy. The scope of supply covers a ring-type mechanical assembly with a ceramic servo motor, a linear positioning stage with precision bearings, an optical linear encoder capable sub-micron measuring steps, and fibre-optic lens fixturing.

Heason also supply the servo drive amplifier and motion controller with all interconnecting cable assemblies to carry power and signals through the three separately sealed GRP pods. The specification calls for high acceleration and high speed to maintain the ZephIR’s 20 millisecond measurement window while maintaining the positioning resolution requirement at the microns level over a travel range of 15mm.

As ZephIR can be subjected to hostile environments as extreme as desert summers or arctic winters, and is left unattended in remote areas over several months or even years, all components need to comply with strict performance and reliability specifications. In addition, the instrument’s overall battery power consumption of approximately 100W continuous, requires the motor, drive and motion controller’s power usage to be minimal.