Research And Design Of High-power Phase-shift Full-bridge DC-DC Converter Based On The Fuzzy PID Controller

In an environment of increasingly severe global energy crisis and environmental pollution,with the constant increase of global car’s total amount,the green,energy-efficient new energy vehicles have become an important direction for the development of the automotive industry,and the new energy automotive industry has developed rapidly.DC-DC converter is an indispensable part of new energy vehicles,which provides energy resources for automotive-related electronic components.For the switching power supply in middle-large power applications,the Full-Bridge DC-DC topology is the preferred,which has advantages as the large power output,the good security and stability,and the switch can achieve soft switching technology,etc.Therefore,this paper selects to study the Full-Bridge DC-DC converter.First of all,this paper introduces the current development status of switching power supply,lists the mainstream topology adopted by the current switching power supply market,and divides the Phase-Shifted Full Bridge converter into 12 working modes to carry out theoretical analysis in a single work cycle,clarifies its basic working principle as well as carries out theoretical analysis for the soft switching technology realized by hysteresis and its duty cycle losing problems.Then,carries out parameter design device selection for each constituent unit in converter main circuit,mainly including EMI filter,rectifier module,filter capacitor,filter inductor,power switch,high frequency transformer and other elements.Secondly,this paper establishes a small signal equivalent circuit model of BUCK topology,and obtains a small signal model of Phase-Shifted Full Bridge DC-DC converter on this basis,designs conventional PID controller,fuzzy controller and fuzzy PID controller separately,as well as uses MATLAB software to carry out the performance analysis of the control system.Finally,on the basis of the theoretical analysis of topology,this paper designs each module on the hardware circuit of the control system,including the main circuit,driving circuit,sampling circuit,power supply module and the main control module,selects the DSP28335 control chip to design a Phase-Shift Full Bridge DC-DC converter with maximum power of 1500 W,as well as completes the prototype production,and carries out related test and analysis of the prototype performance.