Research On Converter Control Technology For Direct-Driven Wind Power Generation System

Direct-driven wind power generation is one of the research focuses, and converter control strategy is the key technology. Back to back dual PWM converter is selected to be the study object in this paper, control strategies of generator-side and grid-side converter are both thorough analyzed and simulated.Firstly, for the generator-side, principle and implementation method of field orientation control and direct torque control are researched, and the merits of the two methods are compared and analyzed. Secondly, mathematical model of grid-side PWM converter is established. For the grid-side, principle and implementation method of grid voltage orientation control and direct power control are researched, and improvement method to normal DPC is given.Finally, the coordinate control of dual PWM converter is made to resolve the problem of grid voltage symmetrical sag on the basis of power balance. Through this method, DC voltage stability control can be realized, LVRT ability can be improved. The control method accuracy is confirmed through the Matlab/Simulink simulation.