A Modified Asymmetrical Self-Oscillating DC/DC Half Bridge Converter

摘要

This paper presents a simple novel technique in order to modifying the conventional self oscillating half-bridge series resonant converter which does not allow the control of the power transfer into a self oscillating half-bridge series resonant converter which allows the power transfer control. The proposed new technique consists in controlling the magnetic saturation of a saturable transformer, by using a DC-control current circulating through an additional winding, in order to ensure a variable asymmetrical control as a function of the dc-control current. We can therefore control and regulate the output power while maintaining the switching frequency close to the resonant one. A 600 W, 300 V input, and 24 V output laboratory prototype operating at 110 kHz is built and tested to verify the effectiveness of the proposed converter.