An inductive filtering method for power quality improvement of large-scale wind farm

An inductive filtering method is proposed for improving the power quality of current grid-connected wind power system, such as voltage fluctuation, frequency instability and harmonic problem. This filtering method can efficiently utilize the inherent ampere-turns balance characteristic of coupling transformer to suppress harmonic components nearby harmonic source. First, comparing the traditional passive-filtering-based grid-connected wind power system and the new inductive-filtering-based grid-connected wind power system, this article analyzes the topology structures and characteristics of them in details; Moreover, the single-phase equivalent circuit model of the new grid-connected system is established, based on this, the theory of inductive filtering and reactive power compensation are expounded, and the principle of tuning device is obtained; Finally, the simulation models of the new and the traditional grid-connected wind power system are established based on PSCAD/METDC. Through contrastive analysis of the simulation results, the superiority of the proposed method in harmonic suppression and reactive power compensation was verified.