Abstract: The small signal model of the closed-loop control system for the DC/DC switching power supply in s-domain is built.The digital compensator design is based on digital redesign approach.The analog compensator in s-domain is designed firstly using Bode plot and root-locus techniques，and discretized to a z-domain compensator.The delay effects associated with the AD converter and the DPWM circuits are introduced to build block diagram of the system，so that the impact of sampling rate is considered to improve the design.The digital compensator achieves accurate and programmable control of PWM regulation to ensure high dynamic performance for the closed loop operation of the converter.The simulation results verify the performance of the compensator.

Key words: digital control systems, analog to digital conversion, digital redesign approach, digital compensator, digital pulse-width modulation

摘要： 建立了数字控制DC/DC开关电源闭环系统的s域小信号模型，采用数字重设计法针对给定的系统参数设计了数字补偿器。应用SISO Design Tool仿真平台，在伯德图分析和根轨迹法的基础上设计了连续域的模拟补偿器，并进行了离散化处理。在建立系统s域模型时引入了模数转换器和数字脉宽调制发生器产生的延迟效应，使补偿器的设计考虑了采样速率对系统的影响，改善了传统离散设计的误差。基于数字重设计法构建的数字补偿器实现了对脉宽调制信号的可编程精确控制，保证了变换器闭环工作良好的动态特性。仿真实验结果验证了所设计的数字补偿器的性能。

关键词: 数字控制系统, 模数转换, 数字重设计法, 数字补偿器, 数字脉宽调制