Transient model equivalent calculation method suitable for doubly-fed fan wind power plant

Abstract

The invention discloses a transient model equivalent calculation method suitable for a doubly-fed fan wind power plant, which belongs to the field of fault modeling calculation of a power system. Sampling is carried out according to the rotating speed change condition of each doubly-fed wind turbine generator in the wind power plant during the process of external voltage drop fault in the wind power plant, weighted dynamic time bending distance calculation between units is carried out based on unit rotating speed time sequence data obtained by sampling, aggregation of wind turbine generators is carried out according to the distances, grouping of the units in the wind power plant is thus realized, the wind turbine generators after grouping are subjected to unit parameter aggregation, current collection line equivalent transformation is carried out on the line impedance based on the principle that power consumption of the current collection line before and after equivalence is equal, andfinally, a grouping transient equivalent model suitable for fault analysis is obtained for the doubly-fed fan wind power plant. On the premise of ensuring the equivalent precision of the wind power plant, the fault simulation time of a power system containing a large-scale wind power plant can be shortened, and better engineering practicability is achieved.

Description

technical field [0001] The invention belongs to the field of fault modeling and calculation of power systems, and more specifically relates to a transient model equivalent calculation method suitable for doubly-fed fan wind farms. Background technique [0002] With the deepening of wind power research and the advancement of technology, my country's wind power generation is gradually moving towards large-scale and industrialization, which makes the penetration rate of wind power in some areas continue to increase, and the capacity of wind farm units continues to increase. The grid-connection point of wind turbines has been upgraded from the initial low-voltage distribution network to the high-voltage AC-DC transmission network. The increase in voltage level has led to more attention to the interaction between wind farms and power systems. The impact of wind farms on the power grid has changed from the local voltage deviation and harmonic pollution caused by the intermittency ...

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Problems solved by technology

However, this method is related to the time length of the selected operating data samples and the representativeness of the time period. The dispersion of the sample group will lead to a large number of clusters, resulting in low simulation efficiency.

In addition, doubly-fed wind turbines are very sensitive to voltage drops. The deeper the port voltage drops, the stronger the transient changes and the more complex the coherent characteristics

The equivalent method based on the relationship between wind speed and power lacks the equivalent value of wind farms under voltage drop faults, and the steady-state operation data is insufficient. The fitting accuracy of this model for the fault current contribution of wind farms and the interaction of voltage under transient processes is not high enough.

The existing collector line equivalent method ignores the aggregation of units at any position, and the accuracy of the obtained impedance model is not high

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