Study On The Current Control Methods Of Three-phase VSR With PWM

PWM rectifier achieves several advantages, such as high power factor, low THD(Total Harmonic Distortion), bidirectional power flow, etc. So it becames one of the most popular research issues.There are fewer products, and most of them are still in the labs.Three-phase voltage sorece rectifier(VSR) are usually controlled by dual closed-loop control scheme.The current control is the key to achieve the high performance.This paper studys on several current control methods though simulation to achieve the method which matches the requirement, and proves it by the experiment.The most work are done by using the SimPowerSystem of the Matlab6.5.1.The method which matchs the requirement are given in this paper. Some work of the experiment has been done. During the simulation, this paper gives a new current control method using fuzzy logic. Dual- Hysteresis SVPWM current control method and the method to reduce the ac-side ripples are also researched in this paper. In the end, they are ail simulated under unbalance input voltages.Three kinds of basic current control methods are simulated under operation-mode changes, load changes and input voltages changes. The result shows that three kinds of current control methods are all advanced, and equal to the reqirement.An improved current control based on fuzzy logic is proposed in this paper too. The simulation and compare result shows that the improved method based on fuzzy logic maintains the advantages of the Hysteresis SVPWM when stabilizes the switch frequence.All the current control methods are simulated under unbalance input voltages. The simulation result shows that, the methods which are based on the Hysteresis maintain the the advantages both under steady state and variable state; the methods which separate the active power and reactive power and the predictive control of current are all worse.Based on the simulations, the design of experiment is done partly. The TMS320F2812 is used as the controller and the code is finished in C language. The experiment shows that the code of SVPWM is correct.