一种新型原边反馈反激变换器数字采样算法设计

摘要

A new digital sampling control method is proposed in order to achieve high precision for primary side reg⁃ulation flyback converter. The output voltage error can be received from the auxiliary winding of the transformer,and then can be used in the internal control loop to keep the output voltage stable. Compared to traditional digital sam⁃pling method,ADC or DAC is neglected in order to reduce the spending of circuit and power. Based on simulation,a 5 V/1 A AC-DC prototype of PSR flyback converter is used to verify the validity of the proposed sampling method. The voltage accuracy of constant voltage regulation reaches 0.5%. Which indicated that the algorithm has good real-time sampling,accuracy and practicablity.%为了实现原边反馈反激变换器的高精度采样，提出了一种新型的数字采样控制算法。该算法根据变压器辅助绕组两端电压信息调整误差信号大小，并输入到内部控制环路实现对输出电压的稳定调节，相比于传统的采样电路，该方法省去了ADC或DAC电路，节省了控制电路的面积和功率的开销。本算法通过MATLAB仿真，且在一款5 V/1 A的AC-DC电源样机上验证了其有效性，其中恒压精度达到0.5%，表明该算法有很好的采样实时性、精确性和实用性。