Study On The Nonlinear Characteristic Of The Buck-Boost Matrix Converter Inverter

Buck-Boost matrix converter is a new type of power converter with high voltage transfer ratio.It has a series of advantages,such as adjustable input power factor and sinusoidal output voltage.However,the inverter converter belong to the strong nonlinear system structure,sub harmonic,bifurcation and chaos phenomenon is occur under certain conditions,resulting in converter oscillation and irregular electromagnetic noise.Directly affects the quality and reliability of the converter operation.Thus,In this paper,by establishing the state differential equation of the BBMC inverter,deduces the discrete iterative nonlinear mapping model,and deeply studies the nonlinear characteristics of the inverter stage.The main contents include as follows:1,Introduces briefly the basic structure of BBMC,summaries the research status of nonlinear modeling of DC/DC conveter and the research status at home and abroad about the nonlinear analysis of DC/DC converter,and introduces the general framework and content of this thesis.2,Introduces the topological structure of BBMC and its basical working principle,separately introduces the basic principles and specific design methods of related control methods which used in this converter' rectifier stage and inverter stage.3,For the BBMC rectifier stage output PWM modulated DC voltage,the nonlinear characteristics of BBMC inverter under pulse input voltage were studied,namely through establishing the nonlinear model with discrete and iterative of the rectifier stage under the action of the pulse input voltage to analyse the bifurcation and chaos phenomenon and their evolution process of the converter,at the same time,compared with that in the DC input voltage;4,According to the control requirement of the DC voltage with sinusoidal signal of the BBMC inverter output,the BBMC inverter adops voltage and current mode control method.the basic principle of this control mode was expatitated,and the nonlinear model with discrete and iterative of the inverter under the control mode was established,and the influence of the related control parameters on the system stability was analyzed,and the stability domain of related control parameters was determined;5,Using TMS320F28335 DSP as the system controller and IHW30N120R2 IGBT as the main circuit power switch,an experimental prototype of the single-phase Buck-Boost converter is developed,and the theoretical analysis is verified by experiments.