Buck变换器的数字电流滞环控制策略的改进

Improvement to Digital Current Following Control Strategy in Buck DC-DC Converter

基于已有的数字电流滞环控制的Buck DC-DC变换器控制策略和实验结果,分析了造成负载突变时出现动态响应时间长及输出电压无法恢复到期望值的原因,提出了一种改进的控制策略。该控制策略在沿用已有的控制策略的基础上,增加了对负载突变过程的检测,如果发生负载突变情形,自动切换到新的控制策略。针对负载突增和突减,分别建立突变过程的数学模型,设计相应的控制策略,给出硬件测试结果。实验结果表明,该控制策略在稳态控制和动态过程控制中都是正确可行的,在保证稳态时输出电压精度的基础上,明显改善了变换器的动态特性。

Based on the existing control strategy and experimental result of the digital current following controlling Buck DC-DC converter,the reasons why load chances the dynamic response time is long and the output voltage can not recover expected value are analyzed,and an improved control strategy is proposed.Based on the existing control strategy,the improved control strategy adds the detection of the load changes process.If the load changes occur,the new control strategy is switched automatically.According to the shock loading and unloading,the mathematical models of the changes are established respectively,the corresponding control strategies are designed,and the hardware test results are given.The experimental results show that the proposed control strategy is correct and feasible in steady state control and dynamic process control.On the basis of ensuring the output voltage accuracy in steady state,the dynamic performance of the converter is improved.