Research On DC-DC Converter Based On Switching Theory

As the core component of DC power conversion equipment,DC-DC(Direct CurrentDirect Current)converter has attracted the attention and research of scholars in the field of power electronics.In recent years,as the market size of portable electronic devices has exploded,the importance of safe and efficient power conversion components for power supply devices has become more and more prominent.At present,there are many high-efficiency control methods used in the control research of DC-DC converters,but these methods still have some shortcomings,which need to be further optimized and improved.This paper focuses on the research of DC-DC converter control based on switching theory.Based on the existing research results,a novel sampled-data control method for DC-DC converters is proposed,and performance of DC-DC converters is studied based on the switching affine model.The main contents are summarized as follows:(1)A novel error tracking switching law is designed based on multi-Lyapunov functions method and sampled-data control strategy with variant sampling intervals.First,the sufficient condition based on the Lyapunov-Krasovskii functional and linear matrix inequality(LMI)method concerning the state of the constructed switched affine system converging to a finite region is developed,which guarantees the outcome voltage can approach the desired value and achieve the voltage adjustment.Compared with the previous work: the stability condition of the system is independent with the desired voltage value.In this work,for different desired voltage values,one needs to solve the condition once,and the obtained error tracking switching law could guarantee the state converging to the reference point.This method in practical application is more favorable.(2)For the switching affine model of the DC-DC buck converter,based on the Lyapunov-Krasovskii functional with piecewise time-varying Lyapunov matrix and sampleddata control with fixed sampled interval,Sufficient conditions that the switching system is practically stable and the system state converges to the finite region including the reference point is obtained.Finally,the effectiveness and practicability of the method are verified for DC-DC converters by simulation examples.(3)Considering the parameter uncertainty in practical applications,Considering the parameter uncertainty in applications,a robust switching control scheme is proposed,and the stability condition for the proposed switched law is developed.Finally,the effectiveness and practicability of the method are verified for DC-DC converters by simulation examples.