DSP Based Two Phase Interleaved Bidirectional DC-DC Converter

At present the problem of pollution is more and more serious all over the world, energy is becoming more and more scarce, so people need to make a great contribution on the environment and save energy. With the rapid development of auto industry, the use of hybrid cars has attracted widespread attention, the bidirectional DC-DC converter is the key element in the energy management system of hybrid electric vehicle, it can not only reduce the use of energy, but also reduce the emission of automobile exhaust. Therefore, development of a high-efficiency and fast dynamic response of bi-directional DC-DC converter for electric vehicle is of great significance.Firstly, according to the design requirements of the bidirectional DC-DC converter in the hybrid electric vehicle, selects the smaller bi-directional DC-DC converter, according to the characteristics of the multiple parallel, two half-bridge bi-directional DC-DC converter are paralleled and interleaved dual phase half-bridge bi-directional DC-DC converter are composed, explain the advantages of this topology structure in hybrid electric vehicle, and analyze the working mode of converter and the design of the corresponding parameters.Then, dynamic small-signal modes of interleaved bi-directional DC-DC converter under two different operation modes are devived by state-space averaging method for the design of corresponding voltage loop, current loop PI controller, At the same time, the corresponding frequency domain curve is plotted by MATLAB to verify the reasonableness of PI controller. Facing the disadvantage of slow response speed in the experiment, the paper uses the voltage outer loop to add fuzzy control to optimize the PID parameters, to establish the simulation model by MATLAB, the experimental results show that this control method not only improves the dynamic response speed, but also makes the system more accurate.Finally, a small power bi-directional DC-DC converter are done. And the hardware and software of the control system are briefly introduced, after debugging, the output ripple of the voltage outer loop using fuzzy PID control is obtained, the dynamic performance test of the corresponding model is made, and the work efficiency of Boost mode is measured. The experimental results show that fuzzy PID control based on voltage loop using the operation of the converter is feasible.