Energy harvesting is the conversion of free ambient energy, e.g. kinetic energy in appearance of vibrations, into electrical energy. It follows the concept of renewable energy plants, like photovoltaic or wind power, but in a smaller scale. The level of energy harvesting ranges often between microwatts to a few milliwatts. Condition monitoring systems provide information about the structural integrity of machinery or structures. The monitoring is carried out by sensors measuring physical

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... ers and transmit them by radio frequency to a central processing unit. The installation sites are often located in hard to reach areas, which makes the energy supply with batteries not useful, because of the high demand of maintenance. Energy harvesters are a reasonable option; they get installed with the sensors and provide energy over a long maintenance-free period. The aim of this dissertation was the development of an energy harvester, which supplies energy for sensors in rotor blades of wind power stations. Different approaches of energy conversion were pursued and several prototypes were constructed and specified. The energy conversion was carried out either piezoelectrically or electromagnetically. The piezoelectric harvesters were bending beams, in the variants unimorph or bimorph. The narrow frequency range of these structures, in which an effective operation is possible, could be significantly extended by magnets. The low energy yield requires a constant excitation, which makes this kind of harvester less suitable for operation in rotor blades. The electromagnetic harvesters based on solutions with frequency up conversion from mechanical to electrical domain to reach sufficiently large output voltages. Unlike the piezoelectric harvesters, the majority of electromagnetic harvesters were not operated resonantly. The operation takes place in the edge regions of a resonance. It is crucial that the edges of the resonance extend over a large frequency range. Compared to the piezoelectric harvesters significantly larger [...]