Fault ride-through method and system for doubly-fed wind turbines based on explicit model predictive control

Abstract

This disclosure provides a double-fed fan fault ride-through method and system based on explicit model predictive control. This disclosure overcomes the shortcomings of the traditional demagnetization control fixed coefficient, and the demagnetization current can be flexibly adjusted according to the fault situation to fully utilize the rotor. The capacity of the side converter does not require redundant measurement links on the basis of traditional demagnetization control, and can be applied to various fault types and fault depths, suitable for online optimal control, and can meet the requirements of double-fed wind turbines during power grid faults. Transient response requirements.

Description

technical field [0001] The disclosure belongs to the technical field of wind power control, and relates to a fault ride-through method and system for double-fed wind turbines based on explicit model predictive control. Background technique [0002] The statements in this section merely provide background information related to the present disclosure and do not necessarily constitute prior art. [0003] Doubly Fed Induction Generator (DFIG) is widely used in modern wind power generation systems because of its many advantages, such as flexible active and reactive power control capabilities, mature technology, low cost and high reliability. DFIG consists of a back-to-back converter and a wound-rotor induction generator whose stator windings are directly connected to the common connection point of the grid, so are very sensitive to grid voltage fluctuations. With the increasing penetration of wind power year by year, the dynamic behavior between wind turbines and grid has becom...

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Problems solved by technology

[0005] However, according to the inventor’s understanding, the traditional demagnetization control current is obtained by multiplying the measured negative sequence and free flux linkage by a fixed proportional coefficient, and the demagnetization current value obtained in this way may be very large, which will saturate the rotor converter and affect demagnetization. The magnetic effect cannot give full play to the capacity of the rotor converter, and the demagnetization current cannot be flexibly adjusted according to the fault situation

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