Dynamic equivalence and modeling methods and systems for double-fed wind power plant

Abstract

The invention relates to dynamic equivalence and modeling methods and systems for a double-fed wind power plant. The dynamic equivalence method for the double-fed wind power plant comprises: selecting wind power units from the double-fed wind power plant to perform a fault simulation experiment so as to obtain a first group of transient-state active power response curves of the wind power units selected under preset wind speeds at a grid-connection point; selecting a string of wind power units to perform the fault simulation experiment so as to obtain a second group of transient-state active power response curves; performing the fault simulation experiment on the double-fed wind power plant to obtain a third group of transient-state active power response curves; according to the first group of the transient-state active power response curves, the second group of the transient-state active power response curves and the third group of the transient-state active power response curves, obtaining a first group of inter-group partitioning wind speed sets, a second group of inter-group partitioning wind speed sets and a third group of inter-group partitioning wind speed sets, and obtaining an inter-group partitioning wind speed union set; and according to the inter-group partitioning wind speed union set, performing grouping on the double-fed wind power plant, and making each group equivalent to an equivalent wind power unit. The equivalence effect is good.

Description

technical field [0001] The invention relates to the technical field of power systems, in particular to a dynamic equivalent method, modeling method and system for a doubly-fed wind farm. Background technique [0002] Doubly-fed wind farms generally contain dozens or even hundreds of wind turbines. When modeling it, if each wind turbine is modeled separately, it will greatly increase the complexity of the power system simulation model and the simulation calculation time, and even face the problem of "curse of dimensionality". In order to reduce the complexity of the simulation, the dynamic equivalent method is usually used to group the wind turbines into groups, and the wind turbines in the same group correspond to an equivalent wind turbine. [0003] The traditional dynamic equivalence methods mainly include three types: the first method is based on the difference in wind speed caused by the wake effect and wind direction, and performs dynamic equivalence based on the simil...

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Problems solved by technology

[0003] The traditional dynamic equivalence methods mainly include three types: the first method is based on the difference in wind speed caused by the wake effect and wind direction, and performs dynamic equivalence based on the similarity of wind speed; however, this method only considers the steady-state wind speed index, In the case of a fault, the fault equivalent effect of the wind farm is poor, and when the wind speed difference of the wind farm is large, it will lead to an increase in the number of equivalent wind turbines

The second method is: realize the dynamic equivalence based on the coherence of the unit or the action of the controller as the characteristic quantity; Increase in the number of units

The third method is to perform dynamic equivalence based on the similarity of the dynamic response curves of a single wind turbine at different wind speeds; however, the transient response characteristics at the outlet of the wind farm are the combined effect of the transient responses of all wind turbines, not all wind turbines. Linear superposition of unit transient characteristics, this method has limitations

Therefore, the equivalent effect corresponding to the traditional dynamic equivalent method is poor

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