基于UC3842的输出直接反馈式反激变流器

通过分析反激变流器小信号模型,提出了一种新型反激变流器补偿控制方法,分析基于UC3842的反激式开关电源用于输出直接反馈的可行性.该法较之传统控制方法,具有动态响应快、闭环增益高、稳定性好、电压纹波小、负载调整率低、电压调整率低的优点,并且得到了试验的验证.

Output direct feedback of flyback switching power supply based on UC3842

This paper presents a novel method to control the flyback switching power supply through analyzing the small-signal model of flyback circuit. A new application of UC3842 in a flyback switching power supply has been put forward to perform feedback from output directly. By means of the two methods, the small-signal model of CPM flyback switching power supply is established and the trans-function of each circuit is introduced. The simulation result using Matlab is in excellent agreement with the analysis of trans-function. Compared with the traditional control strategy, it has many advantages, such as, faster dynamic performance, higher close-loop gain, better stability, lower output voltage ripple, lower load regulation and lower input voltage regulation, etc. In addition, the new control strategy discards the design of PI network, which leads to choose circuit parameter easily and easier to be stabilized. The experimental results verify the analysis.