Radiated electromagnetic emissions from wind energy conversion systems

In order to ensure radio services like radio broadcasting or terrestrial navigation, the electromagnetic emissions of wind turbines (WTs) must be also taken into account. Due to the enormous metrological effort as well as the dependence on the weather condition which influences the power level of the WT, the idea of measuring the common-mode current I
_cm
(also known as antenna current) on the power line of the WT and estimating the magnetic field based on this quantity arises. Therefore, this paper deals with the time behavior, the dependence of the fed power level and the distribution of I
_cm
along the power line of a WT. Following, a simple procedure for the estimation of the magnetic field of a WT is presented and evaluated. Furthermore, the influence of the metallic tower on the field attenuation is investigated by means of a simple simulation model. The achieved results allow a quick and simple assessment of the emitted magnetic field of a WT.