Calculation method and device of short-circuit current in the whole process of low-voltage ride-through of double-fed fan

Abstract

The invention discloses a method and a device for calculating short-circuit current in the whole process of low-voltage ride-through of a double-fed fan. The method includes: determining the short-circuit current output by the doubly-fed fan to the grid when a short-circuit fault occurs in the power grid and the doubly-fed fan is in the Crowbar input stage; The short-circuit current output by the power grid; determine the maximum short-circuit current and the minimum short-circuit current that the doubly-fed fan outputs to the power grid during the whole process of low-voltage ride-through when a short-circuit fault occurs in the power grid. The maximum short-circuit current and the minimum short-circuit current are used to determine the connection The setting of relevant protection settings in the incoming power grid. This method comprehensively and completely considers the whole process of the low-voltage ride-through of the double-fed wind turbine when the power grid is short-circuited, and the calculated short-circuit current value is accurate and reliable, and has a good match with the actual operation process of the double-fed wind turbine.

Description

technical field [0001] The invention belongs to the technical field of relay protection setting calculation, and in particular relates to a short-circuit current calculation method and device in the whole process of low-voltage ride-through of a double-fed fan. Background technique [0002] my country's wind energy resources are mainly distributed in the "Three Norths" and the southeast coastal areas, far away from the load center. At present, wind power generation has changed from small-scale and decentralized access in the early stage of development to cluster development and centralized grid connection. As a large number of wind farms are connected to the grid in the form of clusters, the impact of large-scale wind power access on the power system cannot be ignored. [0003] Field operation data show that in some areas where wind farm clusters are connected, when a short-circuit fault occurs in the power grid, the wind farm side provides a large short-circuit current to ...

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Problems solved by technology

[0005] In order to overcome the above-mentioned deficiencies in the prior art, the present invention provides a method and device for calculating the short-circuit current in the whole process of low-voltage ride-through of double-fed wind turbines, so as to improve the protection in the power grid caused by the inaccurate modeling of the short-circuit current of double-fed wind turbines in the current power grid protection setting calculation. The problem of insufficient accuracy of the setting value of

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