Method for inhibiting stator current imbalance of doubly-fed wind turbine generator set

Abstract

The invention relates to a method for inhibiting stator current imbalance of a doubly-fed wind turbine generator set. The method introduces a positive and negative sequence vector decoupling module which is based on a double synchronous rotating coordinate system, the stator voltage and the stator and rotor current of a doubly-fed asynchronous generator are resolved into positive and negative sequence components which are based on the double synchronous rotating coordinate system, thus realizing fast decoupling of the stator and rotor positive and negative sequence current; a stator current negative sequence double closed-loop inhibiting network is established to inhibit the stator current imbalance of the doubly-fed asynchronous generator in the condition of power grid imbalance, thus avoiding the problems that the loss and the heat of the doubly-fed asynchronous generator are increased, the quality of electric energy is reduced and the like caused by power grid imbalance, enhancing the adaptability of the doubly-fed wind turbine generator set in the condition of power grid imbalance, limiting the imbalance degree of the power grid voltage within a certain range and ensuring the doubly-fed wind turbine generator set to be free of off-grid run.

Description

technical field [0001] The invention relates to a current unbalance suppression method, in particular to a generator stator current unbalance suppression method. Background technique [0002] As a clean and non-polluting renewable energy, wind energy is currently the most large-scale development and utilization of low-carbon energy. Variable-speed constant-frequency double-fed wind turbines can capture wind energy to the maximum extent at various wind speeds, which is very suitable for the development direction of wind power technology. Since the AC excitation frequency converter only needs to supply the slip power, the requirement on the capacity of the frequency converter is greatly reduced, so that the doubly-fed wind turbine has become one of the main models in the field of wind power generation. The doubly-fed asynchronous generator is a high-order nonlinear strong-coupling multivariable system. Neglecting the space harmonics, magnetic circuit saturation and iron core ...

AI Technical Summary

Problems solved by technology

[0003] Aiming at the deficiencies of the prior art, the present invention provides a method that can suppress the unbalance of the stator current of the doubly-fed asynchronous generator under the unbalanced condition of the power grid, and avoid the increase in loss and heat generation of the doubly-fed asynchronous generator caused by the unbalanced power grid. method for the occurrence of problems such as increase and power quality degradation

Images