一种数模混合控制的AC-DC开关电源的设计

On AC-DC Switching Power Supplies with Mixed Digital and Analog Control

文章介绍了一种数模混合控制的AC-DC开关电源,PFC电路用芯片UCC28180模拟控制,LLC部分及CAN通信用DSP进行数字控制.传统的AC-DC电源做法是把DSP的地取在主变压器的原边,输出端电压和电流用昂贵的线性隔离光耦采样后传递给DSP.本研究的开关电源是把DSP的地取在副边,省去了线性隔离光耦,降低了成本,且增加了输出电压和电流的控制精度.文中给出了基于UCC28180的PFC电路相关参数的详细计算.实验结果证明了方案的可行性.

An AC-DC switching power supply with hybrid digital and analog control is introduced in this paper.In the power supply,PFC circuit is based on analog control of UCC28180,and LLC circuit and CAN communication circuit is based on digital control of DSP.In conventional AC-DC power supply,the ground of DSP is connected with the ground of primary side of main transformer.Therefore,a linear isolation optocoupler samples the output voltage and current and delivers to DSP.In this paper,the ground of DSP is connected with the ground of secondary side,so the linear isolation optocoupler is removed,with the advantage of low cost and high control accuracy of output voltage and current.Parameter calculation of PFC circuit based on UCC28180 is described in detail.Experiment results verified the practicability of the design.