Posters

Abstract

The ZX TM nacelle-mounted lidar is undergoing certification for compliance with the IEC 61400-50-3 standard for wind speed measurement. Compliance with the standard allows the uncertainties of the lidar's wind speed measurements to be assessed in a thorough and systematic manner. The ZX TM is a circularly-scanning continuous-wave lidar, which allows measurements at a number of heights with respect to the base of the turbine. The lidar measures at a programmable set of ranges in front of the wind turbine, which means that the height above the local terrain of the actual measurement volume will vary as the turbine yaws. Part of the process described in the standard involves evaluating the effects of varying terrain height on the measurement uncertainty. Different measurement uncertainty values are to be expected depending on whether, and how, any variation in terrain is accounted for. In this poster, a worked case study is presented in which measurement uncertainties are calculated both with and without terrain correction for a ZX TM on a turbine in quite simple, but not completely flat, terrain. The results will show the level of measurement uncertainty that can be achieved with the ZX TM lidar and confirm that correcting for varying terrain height gives a significant decrease in measurement uncertainty. Full details will be provided in the poster.