数控有源箝位正激变换器的分析与设计

主要阐述了基于单片机控制下的改进型有源箝位正激变换器设计。实现宽范围电压输入、宽范围电压输出、输出电流可调等功能;具有过压保护、过流保护功能;能够较好地实现主开关管、箝位开关管的零电压开启,大大降低了开关损耗;采用同步整流技术和软开关技术进一步提高系统转换效率;处理器能够根据负载变化自动调整工作模式,即轻载模式、重载模式、待机模式。采用高速光耦合器隔离驱动方式,使得输出电压信号、电流信号直接反馈至PWM控制器,提高了闭环控制带宽,并且具有线性反馈等优点;处理器可根据输出电压或电流参数,并行调整PWM工作频率、占空比,实现PWM&PFM综合控制。经过实际电路制作验证了方案的可行性,说明数字电路结合有源箝位正激变换器具有更多优点。

Design & analysis on digital controlled forward converter with active-clamp reset

The design of improved forward converter with active-clamp reset was explained,which realized the functions of wide range voltage input and output and the adjustable input current with over-voltage and over-current protection.The designed converter could realize zero voltage switch(ZVS),and reduce the power dissipation.The synchronous rectification method and soft switch were adopted to improve the conversion efficiency of the system.MCU could automatically adjust the working mode according to the load.The high speeds optical coupler was used to isolate circuit between the main single circuit and the driven circuit.The simulation results verify that the digital control has better performance with more functions of switch power,and especially controlling the forward converter with active clamp reset.