Research On DSP-Based Voltage-Source PWM Rectifier

With the problems of eliminating harmonic pollution and improving power factor become more and more obvious, and the shortage of global energy, the rectifying devices which use diodes are becoming no more practical. However, the PWM rectifiers which can solve the disadvantages of diode rectifiers become a research hotspot now. Three-phase voltage-source PWM rectifiers (VSR) have advantages that current on AC side is sinusoidal, the power factor can adjust and even more can work in the condition of unity-power factor, and its energy can flow on two-way, so VSR can solve the problems of harmonic pollution, improving power factor and energy efficiency well.Thesis take VSR as the research object, describes its principles, control methods, and designs hardware platform and software programs of VSR based on DSP which type is TMS320F2812, conducts a series of experiments on the VSR, finally have obtained the experiment conclusions.First given the circuit topology of one-phase and three-phase VSR, then analysis their work manners and principles separately from two angles, one is the relationship of voltage and current vectors, and the other is active and reactive power expressions. Establish mathematical models of VSR in three-phase ABC coordinate system and two-phase synchronous rotation d-q coordinate system, and then introduce the control methods of VSR, it is divided into direct current control method and indirect current control method. D-axis current and q-axis current are strong coupled in the mathematical model based on the d-q coordinate system, so using the method of feed-forward decoupling to decouple them in the control algorithm, this control algorithm can make VSR system easy to control. Thesis uses this control method to make a series of system experiments.In the system experiments, Thesis calculates the values of components in the VSR topology and designs PI parameters in the feed-forward decoupling control method, then using Simulink of MATALAB to simulate the whole system, and have obtained the expected experimental waveforms. So begins to establish the hardware platform of VSR system and write programs. After continuous debugging, finally obtain the real waveforms and verify the functions of VSR.