Design And Implement Of Bi-directional AC/DC Converter Based On DSP

In the real electrical power system, with the impact of the application of powerelectronics devices increasingly widespread and motors, transformers and other non-linearloads, harmonic and reactive are become more and more serious. It brings many questions forthe electrie power transmission and distribution system and the other neighbor electricalequipment. However, the PWM bi-directional AC/DC converter has the advantages of highpower factor, low harmonic pollution and a two-way flow of energy, so it has has a broadapplication prospects.Firstly, the development and research situation of the PWM bi-directional AC/DCconverter are analyzed in this paper. The advantages and disadvantages of differenttopological structure and control strategy are also analyzed and compared. On this basis, thesingle-phase voltage source PWM bi-directional AC/DC converter is analyzed in detail,including the working principle, the mathematical equivalent model and control strategy. Atthe same time, on the basis of the introduction of the switching function, the waveform of thebi-directional AC/DC converter under the single polarity PWM modulation is analyzed. Inaddition, the system overall design and detailed design process are given in this paper. Thehardware design focuses on the detailed design process of the converter’s main circuit, controlcircuit, sample conditioning circuit, including the main parameters’ calculation and selectionof main device. The software design is based on TMS320F28035as controller, writing thesoftware design process in detail. The control strategy of the bi-directional AC/DC converteris also discussed. Meanwile, the indirect current control and direct current control arecompared. In addition, the voltage loop and current inner loop PI controller are design anddigital implemented in detail under the direct current control.On the basis of theoretical research, a800W single-phase bi-directional AC/DCconverter is designed in this paper. Waveforms of switch, the network side of voltage andcurrent working on the rectifier mode and inverter mode can be obtained according to the prototype test. It proves that the theoretical research and design method in this paper arereasonable and feasible.