Study On Permanent Magnet Wind-Driven Generator Side Converter Based On DSP

With the increasingly fierce competition in the energy field and the increasingly serious environmental problems, countries all over the world pay more and more attention to sustainable development strategy. As a key technology of the sustainable development strategy, wind power has become a world research hotspot.Due to uncertainty and uncontrollability of wind energy, the terminal voltage of wind generator and dc bus voltage have usually large fluctuation. If the machine side converter is unrestricted, the power fluctuation not only will affect the economics of the grid operation, but also may threaten the users. At the same time, With the increasing of total installed capacity of wind turbine systems, power factor problem may become more and more obvious. Therefore, it is an urgent task to formulate the corresponding control strategies improving the output power quality of direct driving wind system.In this thesis, power factor regulation and unit power factor control strategy of machine side converter are discussed. Meanwhile, in order to keep dc bus voltage stability, this thesis uses machine side converter and dc chopper coordination control strategy.This machine side converter uses three-phase voltage source PWM rectifier as main circuit structure, and adopts double closed loop system composed by voltage outer loop and current regulating loop. In order to estimate the generator rotor position, this thesis adopts digital PLL to realize speed sensorless technique. Through analyzing the three-phase voltage source PWM rectifier circuit, this thesis gives the digital PI adjuster parameter design method in detail. In addition, this thesis also gives a machine side converter input inductance and filter capacitor parameter calculation method. In order to validate the feasibility of the design system, this thesis uses MATLAB/simulink to conduct a lot of simulation analysis on designed system. Finally, this thesis achieves joint simulation of machine side converter and dc chopper, and the simulation results verifies the correctness of the system, but also has very important instruction meaning on building experimental platform.Finally, based on the theoretical research and simulation analysis, an experimental platform applied to permanent magnet direct driving wind system machine side converter and buck chopper is set up by using the digital signal processor(DSP), PIC microcontroller and integrated intelligent power modules(IGBT).Finally, in order to verify key technology of designed system, this thesis uses a 7.5 kW permanent magnet synchronous motor to simulate permanent magnet direct driving wind system. The experimental results show that the design system accomplishes its function.