Research On Feedback Linearization Method Of Voltage-source Pwm Rectifier

Using traditional power diode or thyristor rectifier, for simple structure and mature control technology, circuit has always taken the leading role of rectifier circuit. But with the development of green energy technology, the traditional rectifier's shortcomings of uncontrolled rectification and phase-controlled rectification are increasingly apparent, including issues such as low energy use, injecting a large number of harmonic current into the power system, without two-way flow of energy. So, with all control-type switching devices, the PWM rectifier has come into being. Switching devices'action is controlled through reasonably PWM modulating signal. Then adjustable power factor, the sinusoidal network side ac current and two-way transmission of energy can be achieved, which truly achieves the green transformation of power energy, opening a new chapter in energy using. However, as for its control strategy, from the initial indirect current control to the direct current control, then to the nonlinear control, with the continuous improvement of the performance requirements for the rectifier, the control strategy has also continued development and made progress. With a more cutting-edge methods, that is feedback linearization control strategy in nonlinear control method, this paper conducted a comprehensive study on the voltage PWM rectifier.Firstly, this paper makes a specific analysis on the principle of the PWM rectifier, given vector relationship between the rectifier voltage and current. Based on different combinations of the switching actions and network side ac current, it can be concluded operating characteristics of the PWM rectifier. Then combined with space vector pulse width modulation (SVPWM) technique, the specific action and function of rectifier switching can be obtained. At the same time in three coordinates, mathematical models of PWM rectifier are established.Secondly, based on the research of feedback linearization control theory, concluding input state feedback and input and output feedback, which two methods of feedback linearization are given. Combined input-output feedback linearization method, it is derived for the PWM rectifier control strategy and block diagram can be given. Finally, by the configuration of the system poles, the feedback coefficient of control block diagram can be got.Again, for the PWM rectifier, a system simulation model in the Matlab/Simulink has be set up. Then under the four conditions of system starting, load changing, a given change in the DC voltage and periodic load disturbance in the load side, it's then given the simulation experiment comparision and analysis of the traditional PI control and feedback linearization control.Finally, by setting up of system hardware platform based on 32-bits microcontroller TC1166 of Infineon Company, and compiling the program code, the experiment of the PWM rectifier feedback linearization control method is done. The result shows that the thesis of the proposed control strategy is feasible, and the system has good dynamic and static performance.