Research Of ARM7 Based Digital Control Zero Voltage Zero Current Switching Full-Bridge DC/DC Converter

The digitalization of power supply has become a trend and the soft-switching technology has become a hot spot in power supply field now. The combination of these two directions must be very helpful in improving the power supply's effect and control precision, reducing its volume and improving its power density. This thesis attempts to do some work in combining digital control and soft-switching technology. In this thesis, a novel zero-voltage zero-current full-bridge DC/DC converter which based on digital control by ARM MCU was designed.Based on analysis of the novel converter's working principle, the parameters calculation equations were derived and the main circuit of the converter has been simulated by PSpice 9.2 successful, the performance of the converter which caused by all parameters has been analyzed and the optimized design parameter has been given out. The digital control system which based on ARM MCU LPC2214 has been designed. The software of control system realized the acquisition of feedback signals, the output of PWM phase-shift control signals, the control algorithm and man-machine interface. After that, some analysis on zero-static-error quadratic-optimal PID parameter setting theory has been given. After theoretical analysis and simulation, a digital zero-voltage zero-current phase-shift full-bridge converter was designed, its power is 500W. The key design process of main circuit, driving circuit, control circuit, protect circuit and high-frequency transformer has been given in this thesis. The converter's key working waveforms have been given in the last of the thesis.The experiment results show that: The topology of the novel zero-voltage zero-current converter is reasonable, the parameter design is right, all the results are coincide well with theoretical analysis. The converter can realize the zero-voltage switching of leading leg and zero-current switching of lagging leg. After employed digital control, the hardware of converter has been greatly simplified and the control method is flexible. The converter also has good man-machine interaction function. So this converter has high practical value.