Study On Control Strategy Of Machine Side Converter Based-on VIENNA Circuit Of The Direct-driven PMSG System

With the continuous development of the industrial, the energy consumption further increases and the energy shortage problem has become increasingly prominent, This promotes the development of renewable energy largely. Wind power is one of the highly representative and promising renewable energies. Currently, the DFIG(doubly-fed induction generrator) and PMSG(permanent-magnet synchronous generator) are the mainstream typies. DFIG technology is more mature, and more popular than PMSG in the past years. But in recent years, with the improvement of permanent magnet materials and the improvement of power electronic devices’performance, the PMSG is developing rapidly, and gets more and more attentions.The task of this subject is the study of PMSG system. So far, the rectification part of the experimental platform of the PMSG system has been completed. The work in the theoretical analysis aspect is mainly aboat the establishment of mathematical model. Including the PMSG’s mathematical model under the three-phase stationary coordinate system and the two-phase synchronous rotating coordinate system and the VIENNA circuit’s mathematical model under the three-phase stationary coordinate system and the two-phase synchronous rotating coordinate system. Based on the mathematical model under the two-phase synchronous rotating coordinate system, the control strategy of the VIENNA circuit has been analysed and the double-loop PI regulator has been designed. All of these work Guaranteed the Correction of this system and the stable operation of this system in the state of Unity power factor rectifing. In addition, this subject analysed the problem of the midpoint voltage imbalance of the VIENNA rectifier, and proposed the solution. Then,in the purpose of using the VIENNA rectifier in the PMSG system, this subjet gived the analysis of the problem in the mode of Simulated wind power system. The specific implementation approach is connecting the VIENNA rectifier to the output end of the synchronous generator’s stators to achieve the rectifying operation under the mode of Simulated wind power system. Considered the features of the PMSG, we can know that the amplitude and frequency of the induced electromotive force of the PMSG changes with the rotate speed’s change of the PMSG.. So, these problems take a higher demand to the control system.Finally, by using Matlab/simulink, the simulation of system control strategy and the regulator is validated, and the experiments are implemented through TMS320F2818DSP with C program language. The result of simulation and experiments proves that the system control strategy and the regulator is available and accomplishes the related tasks.