Measured Structural Loads for the Micon 65/13

Structural loads data were acquired for the Micon 65/13 wind turbine operating in the San Gorgonio Pass, California. The loads data were used to identify those operating and atmospheric conditions that resulted in the highest peak-to-peak blade and low-speed shaft loads and the relative frequency of these loads. The extreme deterministic load condition was attributed to mechanical rotor braking with generator-switching being another lesser contributor. Multiple turbine arrays, atmospheric conditions, and topography were identified as contributing factors resulting in coherent turbulence responsible for extreme stochastic loads that occur at wind speeds well above peak power. A by-product of coherent turbulence that occurred at wind speeds close to rated generator power were infrequent power spikes that exceeded the generator rating by over 50%. Time history load plots for each of the fatigue contributors are presented with a discussion of the casual effect behind the various loads. The results of these investigation are considered generic to other three-bladed, upwind turbines similar to the Micron 65/13.