反激式变换器的后级稳压磁放大器双向复位

摘要

磁放大器后级稳压技术广泛应用于改善多路输出功率变换器的交叉调整率.在深入分析磁放大器存在控制死区现象、原因及影响因素基础上,提出一种可以控制死区时间的磁放大器双向复位控制思想及其实现电路,并给出相应的设计指导原则.新控制方法不仅简单,而且可以有效减小死区时间,从而改善极端负载条件下磁放大器的控制死区对多路输出反激式变换器辅输出电压的影响,进而提高主输出的负载可变范围和辅输出的稳压性能.制作了一台三路输出(5V/3A、9V/2A、6V/2A)的反激式变换器实验样机,实验结果验证了新方案的有效性.%Magamp is an effective solution for improving cross regulation of multi-output power converter. By deep analysis of dead time in magamp control and its influencing factor, a new simple bi-directional magamp control scheme is proposed, and the design guidelines are also given. The new scheme effectively reduces the influence of the dead time on the auxiliary output voltage regulation of multi-output Flyback converter under extreme load conditions, resulting in extending the load variation range of main output and improving the auxiliary output voltage regulation. The Flyback prototype converter with three outputs (5V/3A, 9V/2A, 6V/2A) is built to verify the new scheme.