| In recent years, wind power as a new clean energy experienced rapid development, with the the influence of the global energy crisis. Permanent magnet direct-driving wind power generation system has a wide range of applications in the wind power generation units for its good reliability, highly utilization of wind energy and its flexible control system, etc.Although the amount of our country’s total wind power installations has reached the leading level of the world, the further development of wind power technology has restricted by the laggard variable flow unit and the core control technology. This paper focuses on the study of whole power converter and control technology of permanent magnet synchronous direct driving wind generation. The main content can be summed up as follows:(1) This paper firstly introduced the mathematical model of permanent magnet synchronous motor in three-phase static coordinates and two-phase rotary coordinates system. The different topology structures of converter for direct driving wind power system have been discussed. And the modulation methods for converter have been analyzed, especially focusing on sine wave modulation (SPWM) and space vector modulation method (SVPWM), showing results of each simulation analysis. The theoretical research provide theory basis for the follow-up study of the control strategy and control method without current sensor.(2) This paper uses the back-to-back type double PWM converters. Firstly this paper studied the converter mathematical model and control strategy of power line side. The mathematical model of three-phase voltage source PWM rectifier and its equivalent circuit have been displayed. The voltage oriented control strategy and control structure for grid-side system have been given. The three-phase phase locked loop at imbalance power grid has been researched and the simulation result has been given. Then the design of circuit parameters and PI parameters have been discussed, and the simulation model of line-side wind system based on voltage source PWM converter has been built under PSIM simulation environment, which demonstrates the steady and dynamic performance of control strategy of line-side converter system.(3) The control strategy without current sensor, based on the SVPWM has been discussed. Using dc bus current and three-phase switch state the three phase current can be reconstruct, getting to the control strategy without current sensor. After researching on this study, the simulation has been displayed which providing the demonstration of this method.(4) Then, the generator-side converter control technology of the back-to-back double PWM converter topology has been studied on. Taking the zero d-axis current control for an example, analysis vector control strategy based on rotor flux oriented control of the permanent magnetic synchronous generator based on its mathematical model. On the basis of analyzing the line-side converter and generator-side converter control system, control model of direct-driven wind generation system has been built, and the design of generator-side system parameters has been given. After that, simulation about generator-side control strategy has been displayed.(5) Finally, the part hardware and software design of direct-driven wind generation system has been given. In the hardware part, research on op-amp circuit insteading of main circuit has been discussed, and the simulation result and the achievement have been shown. These provide a basis for experimental research on the platform. |
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