Full Bridge Phase-Shift ZVZCS-PWM DC/DC Converter Based On DSP

DC/DC converter is a main part of power electronic converter. Soft Swithing technique is a hotspot of power electronic field. It is 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 and digital control technology, this paper proposes a digital controlled phase-shift ZVZCS full bridge converter and analyses its 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). This paper compares and analyses the two schemes. On the analyses of several typical ZVZCS circuit topologies, a ZVZCS full bridge PWM converter with a simple auxiliary circuit is introduced.This paper composes of three sections:The first one analysis the operation mode of ZVZCS full bridge PWM converter with a simple auxiliary circuit and deduces the circuit equation.The second part introduces the component parameter design of main circuit and then presents the control system both hardware and software.The third part shows the operation performance and analyses the waveform.The Experiment results show:Main circuits parameter is right, reasonable and achieve all design require: Zero-voltage zero-current switching is achieved correctly, and the converter has many advantages such as simple auxiliary circuit, low voltage stress of rectifier diode and high efficiency; The control system's hardware structure is simple, highly integrated and easy to implement; The control system's software works properly and fulfill all functions, the correctness of the whole design is validated.