Research Of Buck DC-DC Converters Based On FPGA

In conventional power electronic technology,controllers for DC-DC converters adoptanalogy circuits to implement voltage control or current control．With the development oftechnology, digital controllers increase cost-effective continuously,control strategies,greatlyimprove stability and flexibility of system,and implement intelligent system easily. Comparedwith DSP，using FPGA can achieve better digital control. Because of FPGA’s rapidity，flexibility and confidentiality, people pay more attention to it in the field of digital control.DC-DC converter based on FPGA is one of the important research directions in powerelectronics field. The main content of this paper is the study and design of Buck DC-DCconverter and uses the digital control based on ALTERAFPGAdevelopment board.The paper analyzes the basic principle of the Buck converter, studies the state spaceaverage model and small signal analysis and builds the power-stage transfer functions. Thedesign parameters for power stage are presented according to system requirements. It focuseson the digital controller of the converter，which is composed of three main functional modules:ADC (analog to digital converter)，digital compensator and DPWM generator. Controlmethod for selection adopts average current control mode using double sampling signals. Thestructure and principle of it are focused on producing and compensation control function isdesigned using MATLAB Simulation, before the digital average current-mode control isdescribed on the basis of that. DPWM generator design according to accuracy and resolutionrequired is achieved by the way of hybrid counter-vibration.After it completed, the article uses QUARTUS II7.2to FPGAsimulation and verifies thecorrectness of ADC controller and DPWM generator. The Buck circuit of hardwareproduction and FPGA-based software design are completed to a satisfactory systemperformance。Last，the simulation and experimental results are gave.