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.

No abstract

In the process of integrating large-scale wind farms into the power system, the harmonic interaction among wind farms causes potential safe and stable operation threats to the power grid. To effectively control the harmonics of the wind power grid-connected system, quantitative analysis of the harmonic interaction is very necessary and meaningful. Therefore, this paper firstly explains the harmonic interaction among wind farms from the perspective of the primary and secondary emission. We use the concept of harmonic impedance to analyze the mechanism of harmonic interaction and proposed a calculation method for quantitative analysis of the harmonic interaction. Using the calculation method, the influence caused by the wind farm self-impedance, the contact impedance, and Static Var Generator to the harmonic interaction are quantitatively analyzed. Finally, taking multiple wind farms in actual operation as a case, the effectiveness of the method is verified by time domain simulation.

These days, the harmonic problem of wind power grid‐connected systems is becoming increasingly prominent due to the increase in the number of large‐scale centralized grid‐connected wind farms and the gradual trend of high‐proportion power electronics for source‐grid loads. The harmonic oscillation caused by power electronic equipment provides large‐scale propagating in the system, and the harmonic interaction makes the harmonic propagation more complex. First, the harmonic interaction of the system is simplified into the radiation relationship between the wind farm and each branch to solve the harmonic current propagation problem caused by the interaction in the multiple wind farms. Then, the branch harmonic current propagation analysis method is used to transfer harmonic impedance and generate the branch harmonic current decoupling. Second, a harmonic current propagation coefficient is proposed to quantitatively analyze the relationship between the harmonic current of the wind farm and the branch. Thereby, the quantitative analysis of the propagation characteristics for the wind farm harmonic current in the system branch is obtained. Finally, abundant simulations verify the effectiveness and feasibility of the proposed method.