Dynamic Characteristic Analysis And Control Research On Memristor DC-DC Converter

DC-DC converter has the advantages of simple topology,easy implementation and high efficiency.It has been widely used in various fields.As a nonlinear system,DC-DC converter could produce nonlinear phenomena,such as bifurcation and chaos,resulting in system instability or even failure due to the influence of circuit parameters,pulse width modulator period and duty cycle.At present,the research on DC-DC converter is mostly based on traditional loads such as resistance,power supply and motor.Memristor,as a basic electronic component rather than resistance,inductance and capacitance,has been a research hotspot at home and abroad since it was proved to exist in 2008,but there is little research on the DCDC converter with memristor load.Taking the DC-DC converter with memristor load as the object,these studies the influence of different memristor characteristics and control modes on its dynamic characteristics.The contributions of the thesis are:Firstly,the chaotic dynamics of memristor DC-DC buck converter under peak current control is studied.Taking the clock pulse period as the bifurcation parameter,it is found that with the increase of the clock pulse period,the duty cycle of the memristor DC-DC buck converter changes from multiple uncertain values to a single fixed value,and the output voltage and inductance current change from chaotic state to periodic state.Selecting a specific clock pulse cycle according to the duty score bifurcation diagram,I explore the dynamic characteristics of the circuit system in a specific clock,and find that it is consistent with the duty score bifurcation diagram.In addition,it is found that the output voltage and memristor flux of the circuit oscillate near the static working point,and the numerical simulation results are verified by building an experimental circuit in NI Multisim.Secondly,the dynamic characteristics of the circuit system are studied by changing the characteristics of memristor resistor and connecting the memristor resistor and resistor in parallel to form MR(memristor-resistor)load and DC-DC buck-boost converter.After changing the memristor model,the circuit system has multiple equilibrium points.Combined with the actual physical significance,the existence and stability of each equilibrium point are analyzed.In addition,the influence of clock cycle on the dynamic characteristics of the circuit system is analyzed.The circuit system shows different dynamic characteristics with different clock cycle.By selecting a specific clock cycle,the time-domain waveform of each state variable of the circuit system and the phase trajectory of the attractor are observed.By adjusting the memristor model and parameters,the output voltage of the circuit system is be close to the quiescent point QP,which provides a theoretical guidance for the application of memristor in engineering.Finally,taking the inductance current and output voltage as feedback components,the dynamic characteristics of DC-DC buck converter with memristor parallel MR load under voltage current feedback control are studied.The switching mathematical model of parallel MR load DC-DC converter under voltage current feedback mode is established,the stability of the circuit system is analyzed,the existence of system balance point is discussed,and it is found that the quiescent point QP of memristor is the stability focus of the circuit system.The influence of the clock cycle on the dynamic characteristics of the circuit system is studied,and it is found that increasing the resistance of R in the parallel MR load can reduce the output voltage ripple and increase the system stability.