Research On Improvement Of Phase-Shift Full Bridge ZVS DC/DC Converter And Its Digital Control Technology

The phase shift full bridge DC/DC converter is usually used in the high-power condition, the main content of this thesis is to design a phase-shift full bridge ZVS DC/DC converter with soft-switching technology and digital control technology, and to improve it.Basis phase-shift full bridge ZVS DC/DC converter has inherent shortcom-ings: its lag leg is difficult to achieve ZVS and with secondary duty cycle losing. First, two strategies are introduced to solve this problem: using a saturable inductor in the converter primary or using an assist resonant network in parallel with lag leg. Then, the second strategy is chosen to improve basic phase-shift ZVS DC/DC converter considering about feasibility and practicality. The simulation result shows that it has achieved desire target. The designing details of magnetic components and other components, such as high-frequency transformer, resonant inductor, assist resonant inductor, output filter inductor, input filter capacitor and snubber network are provided in this thesis. The main components above are built actually. At the same time, the assist power supply to power control circuit in main power supply is built and tested with TOP243Y. With regard to the application of digital control technology, DSP2812 is applied to design the digital controller of main power supply system.Finally, the simulation tool Saber is used to achieve open-loop simulation of the main circuit, and the result shows the theory and parameters of components are correct and reasonable.