【摘要】 实际数字系统中通常采用滞后一拍的控制技术来解决采样及计算延时所带来的变换器最大占空比受限问题,但是又会使得控制系统稳定范围减小。本文以比例控制器为例,分析和计算了滞后一拍对单相PWM整流器输入电流内环稳定范围的影响,提出了一种应用变步长自适应滤波算法对输入电流进行预测控制的方法,由于算法中的加权系数随每个采样周期预测误差进行自适应调整,所以算法具有较好的稳态预测精度。仿真和实验证明,由于输入电流预测算法的引入,在相同的主电路及控制系统参数下,电流内环的稳定范围增大,同时系统具有较好的稳态精度及抗负载扰动的动态性能。更多还原

【Abstract】 To solve the problem that the maximum duty is limited by the delay caused by sampling and calculation,one-step-delay control is usually adopted in the digital control system,but it will reduce the range of stability.Take the proportional controller as an example,this paper analyzes this problem,and proposes a supply current predictive controller which adopts the variable step-size adaptive algorithm.Because the weighted coefficient is regulated by the error calculated in each sampling period,this algorithm shows well predictive accuracy.If the other conditions and parameters of main circle and control system don’t change,the stability range will increase.At the same time good accuracy at steady-state and fast dynamic performance will be presented.Simulation and experimental results testify feasibility of the proposed method.更多还原