Open Access Open Access  Restricted Access Subscription Access

Inertial Energy Harvester for Monitoring Wind Turbine Blades



In order to operate a structural health monitoring (SHM) device for a wind turbine blade, one needs to use a slip ring to siphon power from the turbine’s generator or use a power source inside the blade. An energy harvester mounted inside the turbine blade capturing energy from the blades rotation would be a great solution for powering a SHM device for a long period of time. The low rotation speeds (between 5 and 20 RPM for the many large scale turbines) make it challenging to harvest sufficient power. Previous research into energy harvesters in rotating environments (e.g. automotive wheels and propellers on large ships) has examined much higher rotation speeds (in the range of 100 to 1000 RPM). At the rotation speeds of large wind turbines, these harvesters have either not been tested or they produced only a few hundred microwatts. This paper discusses the modeling and experimental validation of an inertial energy harvester for use in low speed wind turbines to power a SHM device. The harvester consists of a magnet placed inside a slider tube and a coil mounted on the outside of the tube. The harvester assembly is then mounted radially inside the turbine blade. As the turbine rotates, the magnet slides along the tube and through the coil. The moving magnet induces a voltage across the terminals of the coil. This voltage can be stored in a capacitor or rechargeable battery which would in turn supply power to a health monitoring system. This paper will outline the modeling of the harvester, validation of an electromechanical coupling model, and testing a prototype harvester on a rotating apparatus.

Full Text: