Analysis for action degree and influence factors of harmonic interaction in multi-wind farms

With the increasing proportion of wind power in the power system, a significant threat is posed to the safe and stable operation of regional power grids and the consumption of the new energy by the harmonic interaction effects among wind farms. Aimed at the problem of mechanism for the harmonic interaction between wind farms and the degree of influence, an aggregation equivalence method of wind farms in harmonic power loss is proposed, where the complexity of wind farm equivalence calculation is reduced. Based on this, a harmonic impedance model of multiple wind farms grid-connected system is established, and the mechanism of harmonic interaction influence among the wind farms is revealed. The definition and calculation method of harmonic current interaction factor is presented, where the relationship between the harmonic current interaction and the potential factors, i.e., the coupling impedance, the dynamic reactive power compensation devices, and the number of wind turbines connected to the grid among multiple wind farms, is quantitatively analyzed. Finally, a typical wind farm of new energy base in Northwest China is used as a toy example to verify the effectiveness of the harmonic current interaction factor in the characterization of the interaction strength within multiple wind farms.