Research On Single-Phase Voltage-Sourc PWM Rectifier Based On DSP

With the widespread using of the motors, the traditional power electronic converters and transformers, much harmonic and reactive power is injected into the power grid, and depressed the power quality greatly. To reduce this un-green grid loads, Researchers pay more attention to PWM rectifiers. PWM rectifier not only has the advantage of sinusoidal current of AC-side, but also has the advantages of high power factor and low grid current harmonic. These features can make the PWM rectifier to replace the traditional rectifier devices, such as phase-controlled rectifier and non-controlled rectifier, to reduce the reactive power and harmonic pollution on the grid.Firstly, this thesis presents the development of the rectifier and its characters, achievements, applications, with the extensive documentary review of the updated material. The principle of the single-phase voltage source PWM rectifier and the PWM modulation technology are analyzed. The single polarity and dual polarity modulation are analyzed and compared in this thesis. The mathematical expression of relevant variables which are used the single polarity modulation mode is reduced and their waveforms are analyzed.This thesis introduces the control status of the single-phase voltage source PWM rectifier in detail, including the main control modes at present. The transient current Control is analyzed deeply. Current inner-loop controller and voltage outer-loop controller are designed with typical I type and II type system.With the analysis about theory above, the hardware and software of the experiment system are designed. The hardware design contains:LC parameters of the main circuit, Secondary filter design, sampling circuit, protection and drive circuit and so on. The software design based on the DSP controller TMS320F2812 is realizing the transient current Control. Software flow is given in this thesis in detail.Finally, the simulation of transient current control and predictive current control are used by MATLAB/Simulink. The influences of the main circuit parameters variation, the over-voltage and the low-voltage of AC side are analyzed by simulation.