The Robust Control Of DC-DC Converter

With the development of the science and technology and the improvement of social productivity, the requirement for the quality of electric energy is higher than before. As a kind of electric energy processing devices, the switching converter is very important, and the researches on it have attacked more and more scholars’attentions.The Boost converter is studied in this thesis. It is a type of DC (Direct Current)-DC converter, whose function is to obtain a higher output voltage than that of the circuit input. The research status and the development trend of DC-DC converter are summarized in the thesis. Subsequently, a detailed analysis and the researches on the Boost converter are carried out. The internal model control algorithm is designed for the unmeasurable input voltage variation, and the sliding mode control is designed for the load disturbance, respectively. The main research contents in this thesis are as follows:First of all, the principle of the Boost converter is introduced. Based on the state space average method and the small signal method, the mathematical models of the Boost converter are established to design the sliding mode controller and the internal model controller.Secondly, the sliding mode control algorithm based on the state space average model is designed for controlling the Boost converter. The effectiveness of the controller is verified to the case of the load abrupt change, the reference voltage change and the input voltage change, respectively. At the same time, the influence of the load, the input voltage and the reference output voltage on the output voltage ripple of the system are analyzed under the conditions of disturbed input voltage and output voltage with measured error. The influence of the controller parameters on the output voltage ripple is also analyzed. The MATLAB simulations are given to illustrate the effectiveness of the control algorithm. The simulations for the Boost converter are carried out with the two models, i.e., the mathematical model and the real physical circuit.Thirdly, the internal model control (IMC) algorithm based on the small signal model is designed for controlling the Boost converter. Considering the cases of the inaccurate system model without disturbance, accurate system model with disturbance and the inaccurate system model with disturbance, the performance of the IMC system are analyzed. The MATLAB simulation is taken to illustrate the effectiveness of the control algorithm. The simulation is carried out using the real physical circuit. Furthermore, the proposed control algorithm is discretized to realize IMC in experiment setup.Finally, the experimental hardware platform is set up, we designed the FPGA VI program for LabVIEW FPGA module and verify satisfying performances of the two developed algorithms on the platform by actual experiments.