一种DCM峰值电流控制模式AC/DC反激转换器环路的设计

Design of a DCM Peak Current Mode AC/DC Fly-Back Converter

对峰值电流控制模式的AC/DC反激转换器环路进行了研究。通过对DCM模式下电压环路的控制与输出调制函数、反馈和补偿函数的推导,建立了系统的传递函数,并对环路系统的增益和相位裕度进行了定量计算和定性分析;通过设计合理的补偿电路,使环路在全输出负载范围内均具有良好的稳定性。采用Matlab和Hspice软件对环路进行仿真,仿真结果表明,DCM工作模式下,AC/DC反激变换器的环路增益和相位裕度均能满足环路稳定性的要求。

An investigation was proposed for DCM peak current mode AC/DC fly-back converter. In DCM mode, the voltage loop control/output modulation transfer function and feedback/compensation transfer function were derived, so the system transfer function was established. The loop system＇s gain and phase margin were analyzed qualitatively and calculated quantitively. An appropriate compensation circuit was designed, so the loop circuit had a good stability at the full range of output load. It was simulated by Matlab and Hspiee software, and the results showed that at DCM mode, the loop gain and phase margin of the AC/DC fly-back converter both met the requirements of stability for the loop circuit.