The Role of Doubly-fed Motor with Low Voltage Ride Through by Controlling Converter in Wind Power Generation

Abstract

To improve the performance of the doubly-fed wind power converter system, according to the doubly-fed wind turbine system and its mathematical model, a vector control based on doubly-fed wind power converter control strategy and the rotor side stator flux linkage attenuation in the grid voltage drop of the doubly-fed wind power system are proposed. MATLAB/Simulink software is used to simulate different voltage sags and to compare and analyze the changes of stator flux and zero-sequence current between original control and stator flux attenuation control based on rotor side. It is found that when the grid voltage drops by 20%, the impact on the system is small, and when it falls to 80%, it would cause huge damage to the converter. And compared with the original control, the low voltage crossing control based on stator flux attenuation on the rotor side can restore the stable running state of the system more quickly. The results show that the stator flux decay control based on rotor side can make the doubly-fed wind machine transit the process quickly and reach a stable state, which lays a foundation for better control of power grid and reactive power support. The results of this study are intended to provide a basis for the control strategy of the converter in the doubly-fed wind power generation system and the stable operation of the system.