Study Of Nonlinear Dynamic Behavior And Chaos Control In Single-phase Inverter

Single-phase inverters can convert DC power into AC power,and are used in important fields such as new energy power generation,transportation,and household appliances.Due to the use of switching devices with fast switching functions,it is a typical nonlinear system,and there are nonlinear phenomena such as subharmonic oscillation,bifurcation and chaos,which seriously affect the stability performance of the system.The single-phase inverter is researched in this paper.The nonlinear dynamic behavior is studied intensively,which aims to improve the stability,conversion efficiency and response speed of the inverter system.The main research contents of this paper are as following:(1)Regarding the sinusoidal pulse width modulation H-bridge inverter as the research object,and the stroboscopic mapping theory was adopted to establish the discrete model.Effects of the proportional coefficient k and switching frequency _Sf on system performance are analyzed by using the methods such as bifurcation diagram,Lyapunov index spectrum,power spectrum,folding chart,time-domain diagram,stroboscopic graph and Jacobian matrix method.The steady parameter area of the system is drawn through numerical calculation,which can provide the reference for parameter optimization of SPWM-H bridge inverters.(2)According to the working process of H-bridge inverter whith PI controller,the discrete model of the inverter is established.The evolution process of system operating state with the change of system parameters is analyzed by using bifurcation diagram.The steady parameter area of the system is verified through folding chart,which can provide the reference for the correct modeling and stable design of the H-bridge inverter with PI controller.(3)The working principle of the H-bridge inverter by valley-current control was analyzed.The discrete model of the system is established.The nonlinear dynamic behavior in the inverter caused by the variation of input voltage E is studied through the methods such as bifurcation diagram,Lyapunov index spectrum,stroboscopic graph,folding chart and Jacobian matrix method,which can provide theoretical basis for the reliable design of the H-bridge inverter by valley-current control.(4)The nonlinear dynamic behavior in sliding mode controlled H-bridge inverter is studied.The stroboscopic mapping method was adopted to establish the discrete model under power law.The nonlinear behavior under different controller parameters a and k are analyzed by using folding chart,spectrogram and bifurcation diagram,and a special type of bifurcation was discovered,in which diverse multi-period bifurcations exist at the same time.The system stability was analyzed based on fast variable stability theorem,and it can be known that the relationship between the stability domain of the control parameter k and the parameter a,which can provide guidance for the parameter design of the sliding mode controlled H-bridge inverter.(5)Three chaotic control methods such as delay feedback method,extended delay feedback method and Washout filter method,are applied to the nonlinear dynamic behavior control of the SPWM-H bridge inverter,and establish the corresponding discrete model.The range of values of each control parameter is obtained by using the Jacobi matrix stability judgment basis.The effectiveness of the above three methods is verified,which can provide the solution for the nonlinear control of the inverter system.