Research On Nonlinear Optimal Control Of Buck Converter Based On State Feedback Linearization

Switching power supply have been widely used in the aerospace,communications,computer and other fields,due to its features of high efficiency,small size,light weight.Switching converter is the core of switching power supply.Therefore,the research of switching converter has been a hot topic both at home and abroad.The research on the modeling and control of switching power supply converter is one of the hotspots in today's research.As the switching power supply converter operating characteristics,switching power converter has a strong time-varying non-linear characteristics,if the previous linear control method of switching power supply control is difficult to ensure that the switching power supply all operating points can be in a stable state,It is difficult to achieve the overall stability of the system.Therefore,this paper focuses on the modeling method of buck-type converter.By defining the duty cycle D of the switching converter as the control variable,and by defining the pulse function u(t)of the switching converter on and off,the pulse model The modeling method shows that the modeling method preserves the nonlinearity of its system.The experimental results show the correctness and feasibility of this modeling method.In this paper,the buck-type converter system model established by the pulse integral method is used as the object of study.By introducing the theoretical basis of the precise linearization of the Li derivative and the conditions of the precise linearization system,the buck-type converter system model is precisely linearized,Finally,through the above theoretical support,the original linear system is used to deal with the original system to obtain the precise linearization model of the system.This paper research a precise linearization system of buck converter system.Based on the introduction of quadratic performance index and passive theory,a quadratic performance index is proposed to derive the weighting matrix Q,and then use the quadratic The optimal control theory is used to derive the nonlinear optimal control law of the system and obtain the optimal control algorithm of the system.The experimental results show that the control algorithm has good robustness and stability in the Buck converter.The simulation model of simulink is used to design the optimal controller,and the simulation is established.In this chapter,the simulation of buck-type converter is analyzed,including open-loop closed-loop simulation analysis of the original system,constant input under input of nonlinear optimal control system,input disturbance(variable input),simulation of load disturbance analysis.The simulation results show that the proposed algorithm has strong robustness,and it proves the feasibility of the nonlinear control algorithm.