Wind Characteristics and Wind Models for Wind Turbine Design in Japan (1st Report, Analysis of NEDO FT Data on Turbulence Characteristics and New Normal Turbulence Model Tuned to that Result)

Abstract

In order to survey the wind characteristics of Japan where mountainous terrain is dominant, a large amount of wind data (NEDO Field Test data) that includes more than 300measurement sites in Japan were analyzed in detail, particularly on the turbulence characteristics. As a result, profiles of 90% quantiles of turbulence intensity estimated from all NEDO Field Test data are well approximated by the IEC Normal Turbulence Model (NTM). However, the turbulence intensity levels of more than 65% of measurement datasets exceed the most severe turbulence category (category A) in IEC 61400-1 (Ed.3). Therefore, we conclude that the present IEC turbulence model for wind turbine design do not reflect the severe wind condition of mountainous countries such as Japan.It is considered that this is one of main reason for frequent troubles of wind turbine in Japan. In order to overcome this problem, new criteria for NTM were proposed. The suitability of the new criteria to severe wind characteristics in Japan was discussed.