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This study presents an analysis method of harmonic interaction characteristics between direct‐drive wind turbines (DDWTs) based on αβ coordinates and the relative gain array (RGA). First, considering the digital delay of inverters, the capacitive current feedback active damping is applied to suppress the resonance of LCL filter, and the output curr...
Citations
... In addition, the branch harmonic current and node harmonic voltage are uncertain. 11,12 As a result, the influence of gridconnected wind power on the harmonics of the system is further expanded, and the harmonic current propagation quantitative analysis also becomes extremely difficult simultaneously. ...
... Combining (11) and (13), the harmonic current of any branch is the product of the harmonic current emitted by each harmonic source with a certain coefficient, which is the harmonic currents emitted from the wind farm propagate in each branch in a certain proportion. Considering (12), the relationship between the harmonic current of the wind farm and its propagation component in the branches can be obtained by the following equation: ...
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.
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.
