Research On Three Level Six Switch VIENNA Rectifier And Its Control Strategy

The traditional rectifiers which used the uncontrolled device-diode or thyristor have some drawbacks, such as input current distort seriously, power factor low and easily cause electromagnetic interference. With the development of rectification technology, the traditional rectifier is being eliminated from people’s life step by step. Owing to PWM (pulse width modulation) technology has many advantages, such as high power factor, low current distortion rate, fast dynamic response, and so on. So the new rectification technology will replace traditional rectification technology, sooner or later.First of all, this paper introduce the development trend and research situation of three level six switch rectifier’s topology and control strategy, comparing different topology and different control method, at the same time. Then, this paper introduce the principle of three level six switch VIENNA topology and theory in second paper.Because of hysteresis current control method has many disadvantage characteristic, such as the power switch switching frequency changes greatly, load of this system will change the frequency of power switch, the fixed width of hysteresis and the dynamic response of current are closely related, it is necessary to improve the control strategy. So this paper propose a new control method, current automatic track control strategy. During in this article, it not only elaborates the principle of operation, but also sets up mathematical model of current automatic track control strategy. On the one hand, current automatic track control strategy inherits the hysteresis current control strategy’s good stability, easy to realize and a clear control mechanism. On the other hand, current automatic track control strategy also has some excellent characteristic, such as actual current could more quickly to follow the reference current, low current harmonic, current loop has nothing to do with hysteresis width, etc.In order to verification the feasibility and effectiveness of current automatic track control strategy. It not only use MATLAB build up the three level six switch of VIENNA rectifier’s simulation model which under current automatic track control strategy in three chapter, the simulation results initial indicate the correctness of this control strategy; but also build up a model machine around digital signal processor TMS320F28035 in four chapter.At last, the prototype experiment further proves the correctness and feasibility of this control method.