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

TANG Zhao1, WU Guozhong1, XV Huaqing2, MA Hao1
（1. College of Electrical Engineering, Zhejiang University, Hangzhou 310027, China;
2. Bel Power(Hangzhou) Co., Ltd., Hangzhou 310053, China）

Abstract: 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.
Key words: isolated DC/DC converter; secondaryside control; input voltage feedforward