Electromagnetic compatibility aspects of wind turbine analysis and design

Abstract

The paper reviews numerical modeling of arbitrarily shaped wire antennas pertaining to some Electromagnetic Compatibility (EMC) issues in wind turbine (WT) analysis and design. The formulation is undertaken in the frequency domain and based on the related Electric Field Integral Equations—EFIE (Pocklington integro-differential equations for arbitrary wire structures in the presence of a lossy half-space). The influence of a dissipative half-space is taken into account via the rigorous Sommerfeld integral approach. The numerical solution of corresponding EFIE is carried out by means of the Galerkin-Bubnov Indirect Boundary Element Method (GB-IBEM) featuring the use of isoparametric elementswhile the Sommerfeld integrals are evaluated numerically. The corresponding transient response is obtained via the Inverse Fourier Transform(IFT). The computational examples are related to the transient response of WTs struck by lightning and the transient behaviour of the realistic grounding systems for WTs. TheWTs are energized by either an ideal voltage or a current source, respectively. WT is represented by a corresponding multiple wire configuration, while the lightning channel is modelled as an equivalent lossy vertical wire attached to the wind turbine. Furthermore, the grounding system is composed from rings, horizontal and vertical electrodes, respectively.