摘要
基于基本电压模式控制方法,提出了一种适于Buck变换器的改进控制方法。该方法用三角载波对输入电压进行调制作为前馈输入,结合终点预测方法,将RC补偿网络的影响旁路,使得输入扰动和参考变化直接反映到占空比变化上,并对该方法的有效性进行了定量分析。分析表明,占空比的变化由输入电压扰动和参考电压变化共同决定,输出电压的变化仅取决于参考电压的变化,而与输入电压扰动无关。通过对闭环增益的分析,得出该方法下系统的稳定性仅取决于主拓扑参数和分压系数而与输入电压无关。仿真和实验结果表明,改进方法下Buck变换器对输入电压扰动具有本质的抑制能力,参考电压恒定的情况下,输出电压稳定度较好,无暂态过冲现象。
An improved voltage-mode control method is presented for Buck converter.The input voltage is modulated by triangular carrier,which is taken as the feed-forward input.Combining with the end-point prediction,the influence of RC compensation network is bypassed,which makes the input disturbance and reference variation directly reflect to the variation of duty cycle.The quantitative analysis of the presented method demonstrates that the variation of duty cycle depends on both input disturbance and reference variation,while the output variation is just determined by reference variation.The closed loop gain of the system is provided,which shows that the system stability analysis is independent of input voltage.The simulation and experimental results demonstrate that Buck converter with the presented method can reject the input disturbance naturally.When the reference voltage is constant,the stability of output voltage is better than the other methods and the output voltage has no transient overshoot.
出处
《电工技术学报》
EI
CSCD
北大核心
2011年第4期93-99,共7页
Transactions of China Electrotechnical Society
关键词
输入扰动抑制
电压前馈
幅值调制
暂态过冲
Input-disturbance rejection
voltage feed forward
amplitude modulation
transient overshoot
