一种限流电路及其在ISOP系统中的应用

A Current Limiting Protection Circuit and It’s Application in ISOP System

对现有的限流方式进行了分析,提出了一种以输出电流作为依据,对软启动(SS)引脚进行限幅的限流保护方式,来实现系统的整体限流。该方法响应迅速,限流外特性可控。同时,将该限流电路应用到输入串联输出并联(ISOP)系统中,给出了应用电路,并分析了限流电路对于输入均压环的影响,证明了该限流方式不会破坏均压环作用,系统仍然能够进行均压。为了验证该限流保护的可靠性,制作了一台基于ISOP移相全桥变换器的实验样机,进行了实验。实验结果表明,该限流保护电路不仅能够应对过载情况,同时模块可靠均压。

Based on the analysis of the current limiting protection methods,a current limiting protection method based on the output current and the amplitude limiting of the soft start(SS) pin is proposed to realize the overall current limiting of the system.The method has fast response and controllable characteristics outside current limit.At the same time,the current limiting circuit is applied to the input-series output-parallel(ISOP) system,the application circuit is given,and the influence of the current limiting circuit on the input voltage equalizing ring is analyzed.It is proved that this current limiting mode will not destroy the effect of the voltage equalizing ring,and the system can still equalize the voltage.In order to verify the reliability of the current limiting protection,an experimental prototype based on ISOP phase-shift full-bridge converter is built and tested.Experimental results show that the current limiting protection circuit can not only cope with overload,but also achieve reliable voltage equalization.