Loop-shaping method based current sharing controller design for parallel DC/DC converters

Power supplies with several paralleled DC/DC converters are usually used for high reliability purposes owing to their advantage in terms of redundancy and modularisation. However, current unbalance due to parameter deviations among the paralleled converters might deteriorate the whole system reliability and results in excessive thermal and device stress in some individual modules. In this study, an equivalent transfer function derived from the output impedance and the voltage control loop gain. Also, a loop-shaping based robust control method is employed to design a current sharing controller utilising the proposed transfer function. Simulation and experimental results are presented to demonstrate the effectiveness of the proposed method for the parallel DC/DC converter performance improvement.