Design and evaluation of an energy-autonomous ultra-thin wireless sensor node for condition monitoring of wind turbine blades

Wind turbines are installed in remote locations and are exposed to harsh environmental conditions, which have a particularly strong impact on their rotor blades. Therefore, it is of great interest to acquire local measurement data to determine the present state of the wind turbine to enable safe and efficient operation. For this purpose, we present an energy-autonomous, ultra-thin wireless sensor node. The sensor node consists of a planar capacitive sensor for ice layer detection and MEMS accelerometers for modal analysis in regular intervals and continuous peak load detection. The energy-autonomous operation is obtained with a thin-film solar cell designed for low illumination, a constant voltage charging circuitry and a bendable Li-ion rechargeable battery with a height of 450 µm as energy storage. The operational components of the sensor node are evaluated independently, and the wireless sensor node is demonstrated on a small-scale wind turbine blade with a length of 1.07 m.