Design And Research Of Bidirectional AC/DC Converter Based On DSP28335

With the continuous in-depth development of new energy power generation and microgrid technology,AC/DC hybrid microgrid has the advantages of flexible structure,high power supply reliability,and excellent power quality,and has attracted the attention of many experts and scholars in recent years.The three-phase voltage bidirectional AC/DC converter is a bridge connecting the AC and DC subnets,and is the core of the power flow control of the hybrid microgrid.The three-phase voltage bidirectional AC/DC converter can not only work in unit power factor rectification state,but also can flexibly change the grid-connected power characteristics of the inverter to realize two-way transmission of electric energy.It has fast dynamic response,high quality DC rectified voltage,and harmonic power grid.Significant advantages such as small wave interference.This thesis conducts in-depth theoretical and experimental research from different aspects such as uncertainty model establishment and analysis,prototype system design,weak buffeting and strong torsion algorithm simulation,back-to-back experimental system construction,four-quadrant operating characteristics testing and analysis,and detailed introduction of 10 k W three Design method and operating characteristics of phase-voltage bidirectional inverter prototype.The research results have important theoretical research and engineering design guiding significance.At the model building and control algorithm level.Based on in-depth analysis of the system dynamic models in different coordinate systems,considering the uncertainty of physical parameters and external disturbances,a nonlinear uncertainty model of the three-phase voltage bidirectional AC/DC converter is established.In order to improve the dynamic and stable control performance of the system,the control shake caused by the traditional symbol function is effectively suppressed by introducing the double-curved tangent function,so as to realize the control of the weak shake and Super-Twisting of the system.By constructing a simulation model,carrying out a simulation comparison between load mutation and physical parameter perturbation,the superior characteristics of the proposed control algorithm are verified.At the design level of two-way AC/DC prototypes.Through detailed analysis of the parameter design and selection of passive components(filter inductors,filter capacitors),key functional unit circuit design,control software flow design and other content and methods,the design method of the 10 k W functional prototype is comprehensively introduced.The prototype equipment uses TI’s DSP28335 chip as the main controller,and uses CPLD programmable logic controller to construct a multi-function protection system.Through differential acquisition and optocoupler isolation drive circuit,the system finally realizes stable and reliable operation.In order to realize the flexible control experiment of the prototype system,the upper computer experiment software system is designed,and reliable interconnection is realized through the communication interface.At the level of test experimental environment construction and experimental results analysis.Based on the designed two 10 k W prototype equipment,a back-to-back experimental system was built.One is working in rectification state,and the other is working in inverter state.Through the host computer interface,change the input active and reactive current components,and comprehensively test and analyze the inverter’s four-quadrant operation characteristics.The test data is analyzed using Matlab software,and the influence of conducted harmonic interference is analyzed in detail.The experimental results show that the system can output a stable DC voltage in the rectification state,and the ripple is small;in the inverter state,it can output a highly sinusoidal current waveform to meet the grid connection requirements.