适用于副边控制隔离DC/DC变换器的电压前馈电路

Voltage feed-forward circuits adapted to secondary-side control based isolated DC/DC converter

为了实现副边控制隔离DC/DC变换器的输入电压前馈,讨论了解决问题的难点,提出了两个分别基于辅助源变压器和主功率变压器的具体实现输入电压前馈的电路,分析了每个电路的工作原理,并指出了各自的优缺点,然后给出了相应的实验波形,最后在基于副边控制的低压大电流隔离DC/DC变换器样机上作了验证。实验结果表明,所给电路相对简单、可靠,都能很好地实现输入电压前馈功能,对动态响应性能有明显的改善。

In order to realize the input voltage feed-forward of the secondary-side control based on isolated DC/DC converter,the difficult points of solutions were discussed,and two specific circuits which can realize the input voltage feed-forward based on bias-power supply transformer and main power transformer respectively were shown.The operation principle of each circuit was analyzed and their merits and drawbacks were pointed out.Then the experimental waveforms were shown,and isolated DC/DC prototypes based on secondary-side control with low output voltage and high output current were made to verify the analysis.The experimental results indicate that the shown circuits are simple,reliable,and able to realize the input voltage feed-forward function very well,and improve the dynamic response obviously.