Research And Design Of Fuzzy PI Control For Buck Converter

The rapid development of high-performance power electronics combined with the development of high-reliability control chips and advanced digital control technology has given new ideas and methods to the development and application of switching power supplies.As the reliability and stability of power quality are increasingly dependent on the performance of power electronic control systems,the role of good power electronic control systems in electrical energy systems becomes more important.Especially for some occasions with high requirements on power quality,we need to constantly improve and put forward more excellent control strategies to meet the needs of users.As one of the most basic topologies in the power electronics field,non-isolated buck converters have been widely used in electric vehicles,wind power and various new energy equipment.Conventional DC buck converters typically use proportional-integral(PI)control to ensure a steady-state,error-free output of the controlled voltage,but this proportional-integral control method produces a large voltage when the system is not yet stable under system startup.Dynamic fluctuations are overshoots.If the overshoot is severe,electrical equipment may be damaged and the traditional PI control will take a long time to reach steady state.This topic combines fuzzy control with traditional PI control to design an efficient Buck converter.Thesis analyzes the domestic and international status of switching power supply development.To overcome the shortcomings of traditional PI control,the fuzzy control technology is applied to the research and design of switching power supply(Buck converter).In the working principle of the basic Buck converter,the operating state of the converter in the continuous mode of inductor current(CCM)and inductor current interrupt(DCM)is analyzed.On the control strategy of the Buck converter,the Buck transform is performed.The output voltage of the device is controlled by traditional PI technology and fuzzy PI technology.The PI control and fuzzy PI control simulation experiment of Buck converter are completed by Matlab/Simulink.Finally,the main circuit,drive circuit and sampling circuit of Buck converter are designed.The Buck converter prototype was fabricated and the Buck converter was tested in combination with the DSP2812 development board.Compared with the traditional PI control experiment results,the Buck converter has the characteristics of fast speed and high precision,and overcomes the traditional PI control speed.The disadvantage of slow and large overshoot.