Nonlinear Behavior Analysis And Chaos Control Of Improved Multiplier Voltage Rectifier Quasi-Z-Source Inverter

This thesis proposes an improved multiplier voltage rectifier quasi-Z-source inverter(IMVR-qZSI)as the research object.Inverter is a power electronic system composed of a large number of switching equipment,which belongs to a representative strong nonlinear dynamic system.Compared with the traditional voltage type DC/AC converter circuit,the Z-source DC/AC converter circuit ingeniously injects the shoot-through mode into the switching zero state to achieve the voltage rise on the input side of the H-bridge without affecting the normal inverter.However,it will cause more complex nonlinear phenomena of traditional voltage inverter.In practice,these phenomena will cause abundant bifurcation and chaos due to improper parameter selection or external interference,which will seriously affect the system security and stability.Therefore,in order to ensure the stable operation of the IMVR-qZSI inverter,this thesis develops a deep-level theoretical analysis of the whole single-phase inverter with impedance source by establishing an accurate discrete model of the system with two-frequency ripple and combining with various nonlinear analysis methods.On this basis,three kinds of controls are performed on IMVR-qZSI to reduce or even eliminate the nonlinear phenomenon caused by improper selection of its internal parameters or control parameters.The main research contents of this paper are as follows:First of all,the working principle analysis of IMVR-qZSI is divided into DC component and AC component.Under the condition of considering parasitic parameters,the general discrete iteration mapping of power converter is established to guide the construction of the dynamic model of IMVR-qZSI under CCM with frequency ripple in current mode.Second,taking the non-linear dynamic behavior of IMVR-qZSI under the ideal condition(without double frequency ripple)as a wedge,a variety of non-linear analysis methods are introduced to complete the theoretical analysis of the non-linear behavior of IMVR-qZSI.Combining variety of known stability research methods to carry out theoretical analysis,the necessary system parameters in the IMVR-qZSI design are used as bifurcation parameters to determine the stable working area of the parameters,which provides a reference for IMVR-qZSI parameter optimization and stable design.Third,combined with chaos analysis and the stable parameter domain,the parameters of the filter inductance and capacitance of the important components in the inverter system are calculated through related formulas,and the selection or design scheme is determined.It also includes the selection and design of coupling inductor,input inductor,and energy storage capacitor in the impedance source topology.Fourth,the chaotic phenomenon of current mode IMVR-qZSI in CCM mode is controlled.Using parametric resonance perturbation method,time delay feedback method and sliding mode variable structure method respectively,the chaotic bifurcation phenomenon of IMVR-qZSI is controlled,and the corresponding discrete model is established to conveniently and quickly select the appropriate control parameters.Finally,MATLAB simulation analysis and experimental results are combined to confirm the effectiveness of the control.