Research On Hybrid Rectifier Based On Vienna Rectifier And Diode Bridge Rectifier

With the development of new energy technologies and modern smart grid,seek superior performance of power electronic devices become the development needs of modern industry.A device with only a single advantage can't meet the needs of development.So,looking for power electronic devices with excellent comprehensive performance become research hotspot.As an important power electronic device in the power system,the rectifier's performance will affects the safe,reliable and stable operation of the power grid.In recent years,the research of rectifiers is mostly about a single rectifier device.In order to make its performance better and reduce its impact on the power quality of the grid side and the load side,on the basis of traditional PWM rectifier,it is connected in parallel with the diode uncontrolled rectifier to from a hybrid rectifier.From the relatively new topology structure can combine the advantages of the two,increase output power,reduce costs,and have a relatively small size.The advantages of power density and voltage stress have made it a research hotspot.Therefore,the hybrid rectifier has great research significance and wide application prospects in the field of power electronics technology.1.Select and compare the common topological structures of various hybrid rectifiers,and select the hybrid rectifier in parallel with three-phase Vienna rectifier and single-tube boost diode bridge rectifier in parallel.2.Research and analyze the working principle of Vienna rectifier and diode bridge rectifier,and analyze the working situation after two parts are connected in parallel,and establish the mathematical model of Vienna rectifier in different coordinate systems.The state space averaging method is used to model the small signal of boost converter.3.The design of the hybrid rectifier controller is completed.The PI control strategy is adopted for both parts of the rectifier.The voltage loop and current loop controller are designed separately.The Vienna rectifier is added with the midpoint balance control.The Vienna rectifier is established by formula derivation.Double closed loop control structure diagram.4.The SPWM modulation and SVPWM modulation of the Vienna rectifier are studied.Detailed analysis of positive load wave modulation and co-directional carrier modulation in SPWM and the division of different sectors in the SVPWM modulation is studied.The equivalent relationship between SPWM and SVPWM is proved by formula derivation.5.The effectiveness of the mathematical model and control strategy is verified by simulation experiments.The simulation results show that the hybrid rectifier and its control strategy built in the paper have the advantages of short dynamic response time and strong robustness,and have certain applications prospect.