Research On Control Of Grid-Connected Converter Of Doubly-Fed Wind Power Generation System

Wind energy source is a most commercialized renewable energy sources apart from water. The related technology research is needed for wind energy facilities home-made. Therefore, following study is finished, about double-fed wind power generator converter grid-connected control technology, in this thesis.Firstly, the vector equation and mathematical model of double-fed generator have been analysed and the model is further simplified by adaption of coordinate transformation and coordinates directional. Based on double-fed generator equivalent electric, the analysis is made on the flow characteristic of the double-fed generator system power.Secondly, according to the mathematical model of the grid-connected PWM converter, its operating principle and steady-static features are analyzed. According to the double closed-loop engineering design method, The voltage and current double closed-loop control system of the grid-connected PWM converter is designed, under the power grid and voltage synchronous rotating coordinate system. The simulation model of MALTAB/Simulink, of the machine side and grid side of the double-fed wind power system is established. The simulation research is implemented on the DC busbar voltage, active power and reactive power, as the grid-connected converter is working.Next, aiming of the5.5kW wound rotor induction machine, the main circuit of the tested system is designed including:the calculation of alternating current side inductance and direct current side capacity as well as the select of the IGBT and its drive circuit. The smallest system of DSP2812and its peripheral circuit are designed, IGBT driving circuit and its power supply, the program flow chart of DSP2812and the control program flow chat of the grid-connected converter are given.At last, on the established laboratory test platform of the wind power generator system, the relevant theory are testified and part of the experiment wave forms are shown including the DC busbar voltage when started, busbar voltage response, B phase voltage and the voltage on both ends of inductance, sub-synchronous phase voltage and current wave form.