Time-sharing PWM control scheme for isolated multi-output DC–DC converter

摘要

A novel multi-output pulse-width-modulated control scheme based on time sharing is presented and applied to a two-output forward converter. Unlike the traditional two outputs, the main voltage output and the auxiliary voltage output can be controlled independently via two different switching periods and controllers, by inserting one auxiliary switch into the circuit. Put simply, the main turn-on time is used to control the main switch, the auxiliary turn-on time is used to control the auxiliary switch, and there are several auxiliary turn-on times within one main turn-on time. By this means, two stabilised output voltages are obtained with good cross-regulation. The prototype is verified by a 24 V input, the main voltage output, which has a rated output voltage of 56 V and a rated output power of 50 W, and the auxiliary output, which has a rated output voltage of 44 V and a rated output power of 40 W.