A Digital Active DC-Eliminating Method for DC/DC Converters

This letter presents an active dc-eliminating method for dc/dc converters in order to prevent the transformer saturation. The proposed method is based on the asymmetry in the voltage ripple waveform caused by the dc component of the transformer current. The proposed dc-eliminating technique is able to quickly eliminate the dc component of the transformer current during transients as well as steady-state operation. The main advantage of the proposed method is that it avoids transformer saturation without the need for dc blocking capacitor or any use of current sensors and their additional circuitry. Also, since the proposed method is implemented in the control system, it does not create any power losses or distortions in the waveforms. The simulation and experimental results show the feasibility of the proposed technique.