Control Strategy Research On Doubly-fed Wind Power System Grid Side Converter

Today’s world energy and environmental crisis is an important issue of humen’sfuture survival and development, how to find a kind of clean and renewable clean energyto replace traditional fossil fuels is one of the world’s most popular research topic. Amongthe technologies to develop new energy, wind energy is undoubtedly the one which has themost development and prospects new energy. In wind power systerm, DFIG has beenwidely used all over the world, so it has important significance and practice value to studythe GSC control strategy of DFIG.This paper first introduces the research status of wind power generation technologyinland and abroad, analyzes the basic principle of VSCF system and the main controlmethod of GSC. Then establish the DFIG mathematical model of Stator coordinate systemand Two synchronous rotating coordinate system respectively and analyze its operationstate. The article focuses on the GSC control strategy of the converter, including thecontrol methods which under the disturbance and the unbalance grid voltage. When thegrid disturbances, this paper puts forward a current differential feed forward control waythat based on fuzzy PID control method. The current differential feed forward caneffectively accelerate the adjustment time and accuracy of GSC; The parameters of FuzzyPID control can adjust online and improve the system robustness and response speed. Inthe grid voltage unbalance situation, the article has established both the mathematicalmodel of DFIG and GSC, and analyzed the unbalanced grid voltage of GSC PWM controlmethod, concluded that it’s simple and effective for the inhibition of negative sequencecurrent control method. Finally combining with fuzzy PID current differential feed forwardcontrol of GSC, summarize a combined control method of GSC under both thedisturbances and unbalanced of the grid voltage. Then the effectiveness of the proposedcontrol strategy is confirmed through the Matlab/Simulink to establish a model of3MWDFIG.At last the paper puts forward a new control topology of big power GSC, the topologyconsist of three individual series converter, has the sectional ability of low voltage across.It has certified the effective of10MW DFIG model under the circumstance ofMatlab/Simulink.