Research Of Three-phase PWM Rectifier Based On Sliding Mode And Internal Model Controller

Rectifier is the front circuits of most power electronic devices,the size of the harmonics and reactive power injected into the grid depends largely on the rectifier.Threephase voltage type PWM rectifier has the advantages of lowinputcurrentharmonics,unitpowerfactoroperation,constantvoltageoutputandsoon.Itiswid elyusedinthetraditionalbatterychargingandthetreatmentofpowergridpollution.Thepapercompletedthefollowingresearchwork:(1)Based on the topological structure and working principle of the rectifier,the mathematical model of the threephase controllable rectifier is established by using the Lagrangian equation.The transform theory is used to coordinate the mathematical model of the three-phase controllable rectifier to complete the decoupling of three-phase rectifier.(2)The space vector pulse width modulation technique is studied,and the space vector voltage distribution and synthesis are analyzed.And lay the theoretical foundation for the design of mo del simulation software.(3)The sliding mode variable structure control and internal model control theory are studied.The voltage outer loop sliding mode variable structure controller and the current internal model controller are designed.(4)Hardware circuit of three phase controlled rectifier was designed.It mainly includes the parameter calculation and selection of the main control chip,the power switch tube,the inductance capacitor and other components;power switch chive and protection circuit were designed,voltage and current sampling circuit were designed.(5)Related software applications of three phase controlled rectifier is designed.It mainly includes the main program,A/D sampling subroutine,inner and outer ring control interrupt service routine and SVPWM wave generation subroutine.(6)Thesimulationmodelofthree-phasecontrollablerectifierisbuiltbyusingMATLAB/Sim ulinksimulationsoftware.Thesimulationmodelmainlyincludesphaselocked andringscoordinatetransformationsubsystem,SVPWMwavegeneratingsubsystem,controlsub systemandmodulesimulationalgorithm.Inviewoftheabovesimulationmodel,thetraditionalPI Dcontrolalgorithmandtheslidingmodevariablestructurecontrolalgorithmandtheinternalmode lcontrolalgorithmaresimulatedrespectively,verifying the feasibility of the control algorithm.(7)The experimental circuit of three-phase controllable rectifier is built,and the full-load,half-load and half-load to full-load experiment is carried out by sliding mode internal model control theory,verifyingrationality of components parameter calculation and selection of rationality,the feasibility of the system hardware and software design.A large number of experiments and numerical simulation show that three-phase controlled rectifier based on sliding mode variable structure and the internal model control haveagood dynamic and static performance and the low ac harmonic distortion rate,unit power factor operation,small pollution to grid.