Transient Analysis of Grounding System in a Wind Farm Based on Antenna Theory Using Fast Relaxed Vector Fitting Method

As wind farms grow rapidly throughout the world, the grounding system and ground impedance of wind turbine towers under transients have got more important. As a matter of fact, an exact model to testify dynamic properties of grounding system should represent nonlinear effects of soil ionization and be frequency dependent. Some new researches conducted in this issue, all are based circuit theory which does not allow for accurate analysis of aforementioned behaviors. This paper has come to express a new approach to model any grounding system only by few RLC branches in wide frequency range. A new model and some simple formula that is recommended in this paper, represent all effects of transient phenomena of lightning strikes and all analysis have got more easier than other approach. By using this method, there’s no difference between those grounding system buried in cylindrical soils or conical one, multi-layer oil or not, humid soil or not and so on, they all are available for transient analysis. Then the outputs of antenna theory and recommended method are compared and finally the RLC branches are implemented in EMTP and get analyzed. So it’s possible to evaluate power systems under lightning strikes with presence of wind farms.

کلیدواژه ها:

Antenna Theory ، Electromagnetic Transient Analysis ، EMTP ، Grounding System ، Vector Fitting ، Wind farm