Research On Direct Power Control Method Based On PWM Rectifier

PWM rectifier can make the unit power factor and constant output voltage characteristics, the true realization of the green transformation of electrical energy, greatly improve the transmission efficiency and power utilization efficiency. Is the wind power grid power system requirements.Firstly, the status of PWM rectifier technology of simple analysis and introduction, of the PWM rectifier strategy and new PWM rectifier control strategy to be introduced, and expounds the application of PWM rectifier in wind power. This paper first carries on the analysis, lay a theoretical foundation for the later experiment, after modeling and simulation, then verified by simulation software.Secondly, this paper mainly through the research on the voltage oriented direct power control method, establishes the mathematical model of PWM rectifier, and the working principle of PWM rectifier is a more intuitive interpretation. This paper constructs the voltage oriented direct power control system, in this system switch table at the same time control instantaneous active power and reactive power, so how to design the switching table also determines the performance of the system, because the control demand, this paper design method for the switching table into research, through a conventional switching table, find the disadvantage of the conventional switching table, and improvement and obtain better effects of power control. The simulation results verified the effectiveness of the design method of the switching table is improved. Based on the switching table and control of instantaneous active power and reactive power, this article puts forward a new three state direct power control strategy of switching signal. In the new three state switch signal control strategy constitutes a new switching table, the system for active power and reactive power response ability has been enhanced, but also improve the ability of decoupling control system. And through the simulation experiment, the feasibility of this method is proved. At the same time, the simulation results also show the control performance of voltage oriented direct power control of PWM rectifier.Finally, the application of MATLAB/Simulink software, and constructs the model of the PWM rectifier with direct power control, through the simulation experiments respectively on the switching table before and after improvement and the three state switching signal control strategy simulation results are intuitive analysis. The experiment results show that the direct power control based on voltage oriented PWM rectifier has a simple structure, fast dynamic response and high power factor.