1. Analysis Technique for Determining How Complex Wind Conditions Influence Turbines
The installation of wind turbines for electric power generation is picking up pace in Europe, America, and Japan. In the case of Japan, the turbines are being installed in mountainous regions. Hitachi has commercialized downwind turbines that are suited to such locations and have blades on the downwind side of the tower.
There is a need, when installing wind turbines, to estimate their power output and make damage assessments. Past practice has been to do this using wind models that are based on flat terrain like that in Europe. It is difficult using these models to replicate the changes in wind conditions that occur in complex terrain, especially for mountainous regions like those found in Japan, with the problem being that parameters like power output and damage levels are different for each turbine. Accordingly, Hitachi has been working on wind turbine analysis software that uses blade element momentum theory to calculate wind loads and power outputs for the results of wind condition analysis that provide information on wind speeds and turbulence. This means that power outputs and damage calculations can be performed that take account of the changes in wind conditions due to the terrain. Compared to previous methods, this method incorporates the influence of terrain, giving higher power output. In the case of damage assessment, this method also makes it possible to evaluate changes in load that could not be considered by previous methods.
In the future, Hitachi plans to use this technique for engineering purposes when installing wind turbines.