Double-fed induction generator wind turbine Crowbar resistance design method based on fuzzy membership function

A doubly-fed wind turbine and fuzzy membership function technology, applied in wind power generation, computing, electrical digital data processing, etc., can solve problems such as difficulty in achieving the optimal design effect and low efficiency of the trial and error method

CN104682433AInactive Publication Date: 2015-06-03STATE GRID SICHUAN ELECTRIC POWER +1
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2015-06-03
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention discloses a double-fed induction generator wind turbine Crowbar resistance design method based on a fuzzy membership function. The double-fed induction generator wind turbine Crowbar resistance design method comprises the following steps: according to an equivalent circuit model of a double-fed induction generator wind turbine in case of a power grid fault, and with the combination of a maximum fault current limiting condition and a direct-current bus capacitor voltage limiting condition, acquiring extreme value constraint relationship equations of rotor current and the Crowbar resistance as well as the direct-current bus voltage and the Crowbar resistance; respectively establishing fuzzy membership functions of the two constraint relationship equations according to the membership degree function concept of the fuzzy control principle; confirming the cross point of the two fuzzy membership functions in one same coordinate axis, thereby obtaining the Crowbar resistance corresponding to the cross point which is taken as the Crowbar resistance confirmed by using the method. By adopting the method, both the influence of over current of a rotor current transformer and the limiting condition of over voltage of direct current procedures of the rotor current transformer are considered, so that the security operation of the rotor current transformer of the double-fed induction generator wind turbine in a fault period is ensured to a maximum extent.
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Description

technical field

[0001] The invention relates to the determination of Crowbar resistance in a doubly-fed wind turbine, specifically a method for designing the crowbar resistance of a doubly-fed wind turbine based on a fuzzy membership function, and belongs to the technical field of wind power generation. Background technique

[0002] With the continuous growth of my country's wind power installed capacity, a series of problems brought about by wind power grid integration have become more and more prominent. Doubly-fed wind generator (DFIG) is the main type of wind power generation, accounting for more than 50% of wind power grid-connected capacity. The stator of the double-fed wind turbine is directly connected to the grid, and the rotor side is connected to the grid through the grid-side and machine-side converters. Since the capacity of the converter of the double-fed wind turbine is relatively small, when the grid voltage drops, it is necessary to pay attention to the roto...

Examples

Embodiment Construction

[0044] The basic idea of ​​the present invention: first obtain the rated parameters of the wind turbine when the grid voltage is normal, including parameters such as stator-rotor resistance, leakage reactance, and stator-rotor current, and then simplify the wind turbine to obtain an equivalent model circuit when the grid fails, and then obtain the equivalent model circuit according to the maximum fault The current limiting condition and the DC bus capacitor voltage limiting condition obtain the two inequalities that must be satisfied when selecting the resistance of the Crowbar. Finally, the constraint inequality obtains the corresponding fuzzy membership function through the principle of the fuzzy membership function. Through the two fuzzy membership functions in the limit The intersection point within the value determines the crowbar resistance. The invention considers the situation of rotor side overcurrent and DC bus overvoltage in the process of power grid voltage drop, an...