Research Of Improved Pulse Train Control Technique Based On FPGA

In recent years, new energy power generation technology(mainly to wind and photovoltaic power generation) is given more and more attention, DC transform link is the important part of it, due to the natural environmental factors the output voltage characteristics of the wind and solar power is more complicated, so the study of the converter with wide range of input voltage is particularly critical and important. The paper obtains from the research new switch converter control method to improve the performance of the converter input voltage, there are many kinds of traditional switch converter control methods, such as PWM, but the performance of the converter controlled PWM in transient characteristics and stability is poorer, so some scholars proposed the nonlinear control method known as pulse sequence(PT), this method has advantages of simple and feasible, easy implementation, dynamic response ability, good stability, but high and low energy control pulse duty contrast value cannot be set too much which results in that the input voltage range of the PT controlled converter is relatively narrow and limits its application in new energy power generation occasion. Based on the PT control method, a kind of new control method named improve pulse sequence(IPT) is studied in this paper which can make switch converters adapt wide range input voltage, the IPT control method not only retains the advantages of PT, and the IPT controlled converter has the advantage of wide range input voltage and good output performance. The principle and operational process of the IPT control method are introduced in the paper, the output voltage characteristics of the IPT controlled Boost converter is studied and its control rule operating in discontinuous conduction mode(DCM) is also studied. By analyzing the input voltage and the control pulse number ratio, The IPT controlled Boost converter is compared with traditional PT controlled Boost converter. Then the simulation model is built using MATLAB/SIMULINK software to get the simulation waveform. Finally, the hardware experimental circuit is designed by means of the FPGA development platform and the experimental waveforms are given. The main research results are listed as follows:(1) The improved pulse sequence controlled Boost converter steady-state characteristics are analyzed.(2) Improved pulse sequence control parameters are designed and the improved pulse sequence control rules are analyzed and researched based on the relationship between the input voltage and the control pulse number ratio.(3) Using MATLAB/SIMULINK software the IPT controlled Boost converter simulation model is built and the simulation waveforms are analyzed which proves the feasibility of the IPT control method.(4) The FPGA development platform is introduced and the IPT controlled Boost converter hardware experiment circuit is built, the experiment waveforms and simulation waveforms are basically identical which show the validity of the theoretical analysis.