Research On Direct Power Control Strategy Of Double Stator Brushless Doubly Fed Wind Power Generator

With the development of industry,fossil Energy has been overexploited and used,which has challenged the ecological environment and human living environment in today’s world.In order to deal with the ecological environment brought by fossil energy,non-renewable,will eventually dry up a series of problems,the world’s energy is shifting to low carbonization,non-carbonization direction.Wind energy as a clean,infinitely recyclable energy,is being used in large-scale applications around the world,wind power technology has also been rapidly developed.At present,the dual-fed induction generator mainly used in wind power generation system has the disadvantages of low reliability and frequent maintenance,and the permanent magnet synchronous generator has the problems of high frequency converter capacity and expensive cost.As a new type of generator,brushless doubly-fed generator has low cost and no need for frequent maintenance,and has a very broad application prospect in large wind turbine and offshore wind power field.This paper presents a direct power control method for dual-stator brushless doubly-fed wind turbines based on the National Natural Science Foundation of the state,"Research on key basic problems of cage-disabled rotor coupled double stator modular brushless doubly-fed wind power generation System"(Project No.: 51537007),and studies the aspects:Firstly,By consulting relevant literatures at home and abroad,this paper expounds the background,status of wind power generation system in the current field,points out the problems of turbines in the current market,and then determines the research object-double stator brushless doubly-fed wind turbine,The structure,operation mode and energy transfer of double stator brushless doubly-fed wind turbine are studied in detail.Secondly,According to the mathematical model of Tanding brushless doubly-fed wind turbine,combined with the special structure of double-stator brushless doubly-fed wind turbine,the mathematical model of static a-b-c coordinate system and the mathematical model of rotating d-q coordinate system of double stator brushless doubly-fed wind turbine are established,and the equivalent circuit based on the mathematical model of rotating d-q coordinate system is given.And the simulation analysis is carried out to verify the correctness of the mathematical model.Moreover,The direct power control method is applied to the control power tracking bis DFIG stator of a brushless in-depth study of the direct power control strategy and instantaneous power theory,the analysis on the basis of a two-level voltage space converter output vector and their effects,determined sectorized manner and formulated vector selection table,and set up the simulation model.Direct power control method can achieve the tracking control in the novel power generators,may be implemented VSCF generator.Finally,Based on the traditional direct power control method,the three-level converter is used instead of two-level converter to power the control winding,the various spatial voltage vectors of the three-level converter output are analyzed,12 sectors are reclassified according to the effective vector distribution,and the vector selection table is worked out,and the accuracy of power tracking control is verified by simulation.On this basis,the power error comparison signal is added and the vector selection table is re-developed.The improved control effect is significantly improved,especially in the control accuracy,which can completely control the active and reactive power within a given hysteresis width range.