Research On Dual Mode Control Of Doubly-Fed Wind Power Generator

Due to the gradual decrease of traditional energy and the increasingly serious problem of air pollution,wind energy has developed rapidly because of its renewable advantages.China's wind power industry has developed rapidly in the past decade,and the high-speed development areas are mainly concentrated in the 'three north' and southeast coastal areas with high wind speed.However,the energy consumption capacity of these areas is relatively poor,and there is a serious wind eneragy abandonment phenomenon.Therefore,low wind speed areas such as Central China and Southwest China have become the focus of onshore wind power development at this stage and in the future.The doubly-fed wind turbines and permanent magnet synchronous generators are the mainstream wind turbines on the market,and doubly-fed wind turbines have occupied a dominant position in the market due to their excellent stable operation characteristics and high cost performance.Aiming at the shortcomings of low power generation efficiency and high starting wind speed of doubly-fed wind turbines,combined with the electrical topology of permanent magnet synchronous wind turbines,the electrical topology of a doubly-fed wind turbine called'dual mode' is comprehensively analyzed.In this paper,we first understand and study the components of the doubly-fed wind turbine,and analyze the principle of the main components and related mathematical models.In addition,the control strategy of the machine-side inverter in the stator short-circuit mode of the doubly-fed unit and the control strategy of the machine-side inverter in the traditional double-fed mode are studied and designed,and the switching between the two modes is realized.Secondly,based on Matlab/Simulink platform,the simulation model of traditional doubly-fed unit is built and the model is modified into 'dual mode'.The simulation experiment of the designed control strategy is carried out,and the simulation results show that the dual mode control strategy can effectively improve the generating capacity of doubly-fed units at low wind speed.Based on the wind resource data of a low wind speed wind farm,the annual power generation capacity of the wind farm is quantitatively evaluated by applying the 'dual mode' scheme.At the end of the paper,an experimental system is designed based on the dual-mode doubly-fed power generation system,and a monitoring software based on Matlab GUI for the dual-mode experimental platform of the doubly-fed wind turbine is developed.The software can switch the control strategy of the experimental system and monitor the current and voltage of the stator and rotor of the motor in the system.