Research On Modeling And Control Technology Of High Frequency Switch Power Supply

With respect to the linear power supply, the switching power supply has the advantages of high efficiency, small size, light weight, especially the high frequency switching power supply. So it become the most widely used power supply. Therefore, the modeling and controlling technology of the high frequency switching power supply is studied in this paper.Firstly several common bridge inverter topologies are investigated. According to the requirements of the design of high frequency switching power supply, the bridge topology is selected which lagging bridge series diode. Then the paper designs the parameters of the devices which are used in the main circuit in order to achieve zero voltage and zero current turn on and turn off and reduce switching loss of the switching power supply. Through the MATLAB, the result verifies the parameters selection’s reasonable.Then, a small signal mathematical model of switch power supply is set up by using the state space averaging method. Based on the mathematical model, the paper designs a double closed loop control system of switch power supply and proposes a PID control method based on internal model control. To solve the contradiction between the robustness and rapidity of the internal model PID controller, the fuzzy control is introduced. Taking advantage of the online adjusting parameters of the fuzzy control, the control parameters of the system are real-time regulated according to the error and error change rate of current and voltage to make sure that the system has better rapidity and robustness. Through the MATLAB, the result shows that the algorithm is feasible.Finally, the paper designs the control circuit of TMS320F28335, detection circuit, drive circuit and the software process of the control system.