Research On Idle-Load Grid-Connection Of Doubly-Fed Wind Power Generator With Inter-Mode Control Of Rotor-Convertor

Wind energy, as an important renewable, no pollution energy, has been paid great attention by countries in the world on the time of energy sources crisis and environment crisis being serious increasingly, The technology of wind power gets maturity more and more. Grid connection technology of no inrush current becomes a focus of research field of wind power generation with the capacity of stand-alone wind turbine increasing. In oder to enhance robustness and immunity of the system, Doubly-fed wind power generation system is studied in this paper, Internal model control method is applied to the control strategy of double-fed wind generator grid connection in idle-load to enhance the robustness and immunity of the system, which achieve effective control of stator output voltage on idle-load operation of doubly-fed wind generator and smooth transition of the system from idle-load to grid connection.The advantages and disadvantages of three kinds of grid connection mode which adapt to doubly-fed wind power generator are analyzed on the basis of expatiating technical feature of VSCF wind power generation in this paper, common control strategy features of idle-load grid connection are summarized. VSCF theory of doubly-fed wind power generation system and power realtion of doubly-fed wind power generator are expatiated in detail. Doubly-fed wind power generator mathematic model of the three-phase stationary coordinate system and two-phase synchronously rotating coordinate system is inferred.Mathematical model under rotating coordinate system is decoupled based on vector control theory of doubly-fed wind power generator stator flux orientation. rotor side converter current loop internal model control strategy is researched and designed, which achieve stator output voltage good track on frequency, amplitude and phase of the grid voltage on idle-load operation of doubly-fed wind generator. the outer loop power control of the stator and rotor current control as the inner loop control are used to achieve the stator side active and reactive power independent regulation. simulation platform is set up, which uses MATLAB software, simulation authentication is done based on above-mentioned design, the results show good dynamic and tacking performance of the control strategy.Hardware and software design of DSP digital controller are completed based on TMS320F2812, doubly-fed wind power generator idle-load grid connection experiment is completed on 11KW experiment platform, The experimental results verify the correctness and feasibility of the theoretical analysis and control strategy.