Calculation method for short-circuit current of doubly-fed wind turbines considering crowbar action

Abstract

The invention provides a crowbar action-metered double-fed wind turbine generator short-circuit current calculation method. The method comprises the following steps of: deducing a double-fed wind turbine generator short-circuit current equivalent calculation model according to a mathematical model of a double-fed wind turbine generator; and solving double-fed wind turbine generator short-circuit current by combining the current air speed and a pre-stored corresponding relationship list between air speeds of double-fed wind turbine generators and equivalent inner potential values. The method iscapable of rapidly obtaining short-circuit currents of double-fed wind turbine generators under different air speeds, is simple in calculation process, correct and practical, and is capable of layinga favorable foundation for work such as protection setting and the like of electric power systems with double-fed wind turbine generators.

Description

Technical field [0001] The invention relates to a method for calculating the short-circuit current of a doubly-fed wind turbine, in particular to a method for calculating the short-circuit current of a doubly-fed wind turbine that takes into account the action of a crowbar. Background technique [0002] As the proportion of wind power installed capacity in the power grid continues to increase, when the power grid fails, the short-circuit current provided by the wind power site cannot be ignored. Therefore, when selecting the relay protection configuration and setting calculations, the double-fed wind turbine should be short-circuited. The influence of the current on it is taken into account. If you simply regard the doubly-fed wind turbine (DFIG for short) as a synchronous generator of the same capacity, and calculate the setting value of the crowbar protection device based on this, then because of the short-circuit current characteristics of the double-fed wind turbine and the s...

AI Technical Summary

Problems solved by technology

If the doubly-fed wind turbine (DFIG for short) is simply regarded as a synchronous generator of the same capacity, and the setting value of the crowbar protection device of the line is calculated accordingly, then because of the characteristics of the short-circuit current of the doubly-fed wind turbine and the synchronous power generation The short-circuit current characteristics of the unit are not the same, such a calculation method may cause the crowbar protection device to refuse to operate or malfunction

Moreover, the short-circuit current provided by the doubly-fed wind turbine is closely related to the operating conditions. When the grid voltage drops sharply, causing the crowbar protection action, the topology of the doubly-fed wind turbine will change, which will bring further difficulties to the setting calculation. difficulty

At present, there are few domestic researches on the influence of crowbar protection action on relay protection

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