Use of a fiber-optic sensor system to review distributed magnetic field simulation of a wind turbine

According to the Lightning Protection Institute in the USA, lightning damage is the single largest cause of unplanned downtime in wind turbines. The damages can either be caused by direct effects on the structure, or by indirect effects on the systempsilas electronics. Hence, enhanced efforts on the improvement of the lightning protection system of wind turbines have been undertaken to reduce both effects. Therefore, electromagnetic analysis of different elements of the turbine is performed. In order to verify these simulations and to specify the need for shielding inside the turbine elements, the lightning induced field inside the different elements has to be measured and reviewed. In this paper we present a novel approach for potential-free magnetic field measurements, using fiber optic magnetic field sensors based on magnetic garnets. These sensors feature a broad frequency range, an inherent galvantic isolation as well as a low weight.