| DC/DC converter is a main part of power electronic converter. Soft-Switching technique is a hotspot of power electronic research. It's the key technique in high frequency and high density converter. With the advent of microprocessor, there has been an increased interest in digital control of switch mode power supply, instead of analog control. The digital control scheme has many advantages in simplifying the control circuit, improving the anti-interference ability, control precision and flexibility, general and intelligent level. In order to research on soft-switching digital controlled phase-shift ZVZCS operation and digital control technology, this paper proposes a full bridge converter and analyses it's principle of operation.There are two soft-switch schemes of phase-shift full-bridge DC/DC converter: zero-voltage switching (ZVS) and zero-voltage zero-current switching (ZVZCS). The two schemes are compared and analysed in this dissertation. On the analysis of several typical ZVZCS circuit topologies, a ZVZCS full bridge PWM converter using a diode in series with the lagging leg is introduced. Then the main circuit, the driving circuit, the sampling circuit, the protecting circuit and the auxiliary power supply circuit are designed. The method of component parameter design and the design flow of magnetic components such as transformer are also presented. In addition, the simulation analysis of the main circuit is carried out by the OrCAD10.5/PSpice software. At last, on the small-signal model analysis of the phase-shift full bridge ZVZCS DC/DC converter, a digtal control system based on digtal signal processor IC (TMS320F2812) is introduced in this paper. The implementation of the whole digital control scheme is also given in this paper.The simulation results show: Main circuit's parameter is right, reasonable and achieve all design requirements.Zero-voltage zero-current switching is achieved correctly. The correctness of the whole design is validated.
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