具有延时补偿的占空比预测数字控制算法.pdf

2010 年 5 月 电 工 技 术 学 报 Vol.25 No. 5 第 25 卷第 5 期 TRANSACTIONS OF CHINA ELECTROTECHNICAL SOCIETY May 2010 具有延时补偿的占空比预测数字控制算法 孙鹏菊 周雒维 杜 雄 （重庆大学输配电装备及系统安全与新技术国家重点实验室 重庆 400044 ） 摘要 针对开关变换器数字控制中的延时问题，提出了一种基于线性外推的占空比预测控 制算法及其改进的控制算法，该控制算法可利用本次和上一次计算的占空比预测出下一个或下 几个周期的占空比，既能补偿数字控制中固有的计算延时，也能补偿由零阶保持器产生的延时。 和传统数字控制相比，采用占空比预测控制算法可明显提高控制环路的带宽，有效改善了系统 的动态性能。占空比预测控制算法实现简单，不依赖系统模型，不需对系统重新进行设计，简 单有效地补偿了开关变换器数字控制系统中的延时问题。实例分析和实验结果证明了所提方法 的正确性。 关键词：数字控制系统 开关变换器 延时 占空比预测 中图分类号：TP273 Duty Ratio Prediction Control Method With Time Delay Compensation Sun Pengju Zhou Luowei Du Xiong (Chongqing University Chongqing 400044 China) Abstract A duty ratio prediction method and an improved duty ratio prediction method based on linear extrapolation are proposed in order to compensate the inherent time delay introduced by zero-order-hold effect and the computational time delay in digital control systems. The duty ratio of next period can be predicted using current duty ratio and last duty ratio with these methods. With the proposed schemes, the time delay of control loop is compensated and the dynamic performance is improved. It is shown that, compared with conventional digital control, the control loop bandwidth can be improved significantly with the proposed techniques. Experimental results on a point of load DC/DC converter show the effectiveness of the proposed schemes, which demonstrate that the proposed strategies offer a practical and straightforward way to compensate the time delay of digital control switching converters and improve over the existing designs. Keywords ：Digital control system