移相全桥零电压开关pwm设计实现设计.docVIP

移相全桥零电压开关PWM设计实现 摘 要 移相全桥电路具有结构简单、易于恒频控制和高频化,通过变压器的漏感和功率开关器件的寄生电容构成谐振电路,使开关器件的应力减小、开关损耗减小等优点,被广泛应用于中大功率场合。Phase-shifted Full-bridge Zero-voltage Switching PWM Design and Implementation ABSTRACT Phase-shifted full-bridge circuit has the advantages of simple structure, easy to constant frequency control and high-frequency resonant circuit constituted by the leakage inductance of the transformer and the parasitic capacitance of the power switching devices, to reduce the stress of the switching devices, switching loss is reduced,which widely used in high-power occasion. In recent years, with the development of microprocessor technology, a variety of microcontrollers and digital signal processor cost performance continues to improve, the use of digital control has become the development trend of the large and medium-sized power switching power supply. Relative to achieve analog control, digital control has many advantages. The design uses DSP ,the TI company TMS320F28027 series of high-speed digital signal processor, as the controller. The module through the sampling phase-shifted full-bridge zero-voltage DC-DC converter output voltage, input voltage and output current, obtained through real-time calculation of phase-shifted PWM signal phase-shifted full-bridge zero-voltage DC-DC conversion, and then after the drive circuit the four switch control purposes. The experiments show that this control strategy is feasible, and the control module can achieve the proposed control strategy. Key words: phase-shifted full-bridge；zero-voltage；DSP 目 录 　　1　引言 1 　　1.1　移相全桥软开关研究背景及现状 1 　　1.2　本文要做的工作 1 　　2　移相全桥电路的工作原理 2 　　2.1　电路工作状态及特点 2 　　2.2　电路的运行模式分析 3 　　2.2.1　工作过程分析 3 　　2.3　软开关实现的条件 7 　　3　DSP结构功能 9 　　3.1　DSP适合于数字信号处理的特点 9 　　3.2　TMS320系列DSP概况 9 　　3.3　TMS320F2802x芯片特点 9 　　3.4　CCSv5平台 11 　　3.5　利用CCSv5.1导入已有工程 12 　　3.6　利用CCSv5.1调试工程 13 　　4　系统程序设计实现 14 　　4.1　PWM的产生原理 14 　　4.2　主程序的流程图 14 　　4.3　程序设计 17 　　4.4　最终实现的波形图 17 　　5　总结 22 　　参考文献 23 　　致谢 24