Robust and Adaptive Controller for Wind Turbine Blade Testing Machine

The wind turbine blades are made of composite materials and subjected to severe operational loadings. The complexity of composite materials behavior along with variable amplitude loadings dictates the need for experimental setups which can conduct real part test as close as possible to in service loadings. In this regard, wind turbine blade manufacturers are obliged to perform standard ultimate and fatigue tests on their products. In this research a cost effective Blade Testing Machine (BTM) is proposed which is capable of conducting ultimate static and fatigue tests according to wind turbine blade standards. A new control unit is designed and implemented to track fatigue block loading in the frequency range of 1 to 3Hz. The main focus is on designing a controller to perform desired block loading fatigue tests with proper performance. PI and robust feedback controllers are designed and analyzed. Due to the poor robust performance, an adaptive feed forward controller is proposed based on the gain scheduling algorithm. The proposed robust controller compensates un-modeled high frequency dynamics and rejects measurement noises while the adaptive controller compensates low frequency uncertainty and improves reference tracking. Extensive experimentations in the desired frequency range confirm proper performance of the developed controller.