Propagation characteristics and quantification analysis of harmonic current in large‐scale wind farms

Abstract

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.