Research And Design Based On Three Level Active Power Factor Corrector

The three level PFC converter based on VIENNA topology expansion is a device that can actively control harmonic pollution and improve the utilization of power grid.It can realize sinusoidal input current and operate with unity power factor.Compared with the two level topology and diode clamped three level topology,with lots of advantages,this topology has attracted much attention and has been studied.Firstly,this paper briefly introduce strategies of control and development for PFC topologies,analyzes the main topological principle,and then establish the abc and dq coordinate system mathematical model,voltage loop and current loop controller are designed based on the above analyses.In order to improve the utilization of DC voltage,SVPWM is used for this program.and it also cleverly converts three level space vector plane to two level space vector plane,so,it can realize the complex three level space vector modulation with two level space vector modulation.Corresponding research for midpoint equilibrium problem which universally exist in the three level is also carried out in this paper.Secondly,after the above theoretical research,according to the system specification parameters of the project,the parameters of each component of the main topology are analyzed and designed.At the same time,the related auxiliary circuits are also introduced in detail.And Then,three level PFC system was established based on Matlab/Simulink simulation model,the simulation results show that the given voltage and the feedback voltage keep consistent after system start.and the voltage outer loop controller also meet the desired effect,and so,it is proved that the moderating effect of neutral point balance controller PI good.At last,a 10 KW prototype platform for analysis test is built;the parameters,control algorithm and the overall performance of the prototype are demonstrated perfectly.The test results show that power factor of system run with light load is more then 0.9,and runs up to 0.99 after half of load.it demonstrates the feasibility of the theoretical analysis.