Research On Characteristics Of Typical Switching Converter Based On Variable Universe Fuzzy PID

With the development of electronic power technology and intelligent control strategies in recent years,DC-DC converters have become an important part of switching power supplies,mainly used in various fields such as data communication,remote control systems,photovoltaic power generation systems,and green energy.The DC-DC converter is a nonlinear time-varying system,and it is prone to non-linear phenomena such as boundary collision bifurcation and period-doubling bifurcation during actual operation,which will affect the performance and working quality of the converter.Most DC-DC converters now use a single closed-loop control method.When the single-loop control system is disturbed,the output voltage will fluctuate,which will affect the stability of the system.In view of the above situation,this paper proposes a variable universe fuzzy PID control strategy based on the dual-loop mode to control the Boost-Buck converter and the Boost converter.The dual-loop control mode makes the system have a faster response speed to the input voltage change,and the system stability is higher.The variable universe fuzzy controller not only has the advantages of the fuzzy controller,but also uses the expansion factor to improve some of the limitations of the fuzzy control.First,according to the working principle of the Boost-Buck converter and the Boost converter,the small-signal model of the converter is established when the switching states are different;at the same time,the current control strategy applied to the switching converter is introduced and analyzed.Secondly,according to the transfer function of the system,the double-loop mode PID controller is designed using the amplitude and phase margin compensation method;the appropriate membership function and the number of fuzzy subsets are selected,and the fuzzy rule library is designed;then the appropriate expansion factor is selected to complete the change.The structural design of the universe.Then,in the simulation environment Simulink,simulation models of PID control,fuzzy PID control,and variable universe fuzzy PID control are built.The simulation experiment proves that the variable universe fuzzy control strategy of the double-loop mode makes the system stronger in anti-interference ability and higher in system control accuracy.Finally,build an actual circuit test platform based on STM32G474.Experiments show that the variable universe fuzzy strategy has better control effects on switching converters.The results show that the variable universe fuzzy PID control strategy has better control effects in terms of response time and control accuracy.The fuzzy PID control strategy realizes the improvement of the fuzzy PID control strategy.