Study Of Digital Controlled Bi-directional DC/DC Converter

Bi-directional DC/DC Converter can be used to replace two parallel DC/DC converter in the situation which need two-way flow of energy,so it can reduce the size and weight of equipment, and lower the costs. It is in the line with the trend that present power source is needed miniaturization, low-cost, high-frequency-based and efficient.At first, the conception and principle of the Bi-directional DC/DC converter are presented,and its work in definite applications is explained. A novel topological structure of Bi-directional DC/DC Converter is designed, which is used in uninterruptible power supply system. When it is working in the mode of positive direction, converter voltage by transformer series resonant implementation of current zero, and the current of low voltage side reduce to almost zero, then achieve soft switches; When it is working in reverse mode, a auxiliary inductance is added to output proper path, during the follow current period, the auxiliary inductor brings induction electromotive force to reset primary current, so achieve soft switches.And then the theories were tested by Pspice simulation software.This article also studied the revised forecast and fuzzy adaptive parameters of PID control methods, and simulated by simulink to test effect of control. Fuzzy adaptive PID can adjust the parameters of PID timely for the current output signal changes. The output in the next cycle will be predicted and amended so it can compensate the lag time, the predicted values considered uncertain environmental factors so its predictive can be improved. Finally , TMS320LF2407DSP of TI company was used for chip of circuit, and the software design was carried out.