Research On Three-phase Active Power Factor Correction System

With the development of modern power electronic technology, all kinds of power electronic devices and nonlinear loads are applied to power grid, which resulting in a lot of harmonic is injected into the power grid. Active power factor correction (APFC) is an important technology to save electric energy and improve the efficiency of electricity, which can also effectively suppress harmonic in the grid. At present, the single-phase APFC has developed very mature, but the three-phase APFC is still in the stage of developing. Based on the analyze of the current situation of the development of three-phase APFC technology, this paper carry out research on the three-phase APFC topology which made up of three single-phase APFC modules. The main contents are as follows:At first, in this thesis, research status and the future development trends of three-phase APFC technology are introduced, the existing three-phase APFC topologies are presented and the advantages and disadvantages of various topologies are analyzed. The three-phase APFC system which composed of single-phase APFC modules are introduced, and then the three-phase three-wire APFC topology used in this paper is drawn.Secondly, the working principle of the three-phase three-wire APFC circuit is analyzed and the mathematical model of the system is given. On this basis, in order to get the conditions which achieve system stability and unity power factor, the Lyapunov stability theorem is introduced. The scope of the DC output voltage, which for the purpose of realizing the input side current tracking input voltage changes, is obtained by constructing Laypunov function. All of this provides a theoretical basis for simulation and algorithm implementation.Then, the system simulation model is established based on Matlab/Simulink, the simulation results demonstrate that the correctness of the three-phase APFC circuit topology is proposed in this paper. On the basis of the theoretical analysis and simulation, the main circuit of the system and hardware circuit of controller based on TMS320F2812DSP are designed and the programmer code is finished in C language. What’s more, the test datas of the experiment are given, the results show that the input current is able to follow the input voltage changes, and that THD is low. Finally, summarize the text, according to the design goals and the experimental results, article achievements and the work has not been completed and the research shortcomings are pointed out. At the end of the paper, it proposes that the future direction of efforts according to the shortcomings.