Based On Current Controlled DC-DC Converter Chaos Control Research

As the society develops,some precision instruments require higher and higher power supply.The traditional linear power supply has the advantages of large volume and low efficiency,while the switching power supply has the advantages of small volume,high conversion efficiency and various control methods,which make the application scope of switching power supply more and more extensive.As the core part of switching power supply,DC-DC converter contains a lot of bifurcation,chaos and other phenomena.Therefore,it is very important to introduce chaotic dynamics into this field.On the one hand,the use of chaotic dynamics can make us have a more in-depth and comprehensive understanding of the behavior of DC-DC converter,so as to optimize the power supply design.On the other hand,studying chaos from the direction of DC-DC converter can also speed up the development of chaotic dynamics theory.In this paper,the chaotic phenomena in DC-DC converter are studied from the following three aspects(1)The bifurcation and chaos theory of current controlled buck converter,current controlled boost converter and current controlled buck boost converter are studied.Firstly,the working principle of the converter is described in detail,and the discrete iterative model of the converter is established.Then,according to the model,the matlab program is written to get the phase orbit diagram,bifurcation diagram and sequence diagram,and the chaos generation mechanism of the converter is analyzed.(2)In order to solve the problem that it is difficult to determine the amplitude value of the traditional parameter resonance perturbation method,this paper uses the output generated by neural network to act on the perturbation controller,which perturbs the parameters of the chaotic system to achieve the effect of controlling chaos.The genetic algorithm is used to optimize the neural network weight threshold,and the fitness function is used to evaluate the control effect.The experimental results show that the control method can quickly stabilize the working state of the converter in the periodic orbit.(3)Taking STM32 as the main controller of switching power supply,the control circuit,display circuit,sampling circuit and protection circuit are designed respectively,and a practical switching power supply is designed.The parameters are as follows:switching frequency: 72 KHz,input voltage: 5V-30 V,output voltage: 1V-30 V,maximum output current: 3A,output ripple: < 100 m V,output voltage error: < 0.1V.The performance of the power supply can meet the design requirements.