Research And Design Of Bidirectional DC-DC Converter Based On Fuzzy PID Control

At present,the bidirectional DC/DC converter in new energy power generation,electric vehicles,energy saving elevator requires bidirectional DC voltage transformation,the performance of the bidirectional DC/DC converter for the occasions is very important for the reliability of electricity utilization,as well as safety and quality,especially for control performance of the bidirectional DC/DC converter,it is necessary to research a kind of nonlinear control method based on the advanced controller,to improve the bidirectional DC/DC converter operating stability,accuracy and dynamic response ability.This paper firstly classifies the topology of unisolated and isolated bidirectional DC/DC converters,and describes the typical application of bidirectional DC/DC converters,as well as the classification of traditional and advanced control technologies of DC/DC converters.And analyzes the advantages and disadvantages of non isolated type topology and isolated type topology,determine the choice of the topology structure according to application demand,select dual full bridge isolation bi-directional DC/DC conversion circuit,then according to the buck mode and boost mode,analyzes the working principle of the converter,established the mathematical model of the converter,and has carried on the simulation to model,based on the mathematical model of the open loop stability of the converter system are analyzed.On the control strategy research,this paper first presents the design process of the traditional PID control strategy,and analyzes the shortcomings of the traditional PID controller.In order to make up for this deficiency,this paper combines traditional PID control with fuzzy control,gives the design process of fuzzy PID controller,and compares the control effect between the fuzzy PID controller designed in this paper and the traditional PID controller through simulation.In this paper,the circuit realization of isolated bidirectional DC/DC converter is presented,and the design process of power circuit and signal circuit is introduced in detail.At the same time,the controller software program design,including the main program,sampling program,PWM driver program and fuzzy PID control algorithm program flow design.According to the design content,an experimental prototype of 270v-28v voltage bidirectional conversion is made,and the operation effect of the prototype on the isolated bidirectional DC/DC converter based on fuzzy PID control is applied.The experimental results show that the isolated bi-directional DC/DC converter designed in this paper can meet the application requirements.At the same time,the control effect of the fuzzy PID controller designed in this paper is compared with the traditional PID controller in the experiment,and the results show that the fuzzy PID controller adopted in this paper can effectively improve the adjustment ability of the isolated bi-directional DC/DC converter.