Study of cable resistance and remote-sensing scheme in parallel DC/DC converter system via primary droop current-sharing control

Output cable wire resistance and remote feedback sensing scheme have a significant effect on output feedback impedance and might affect the stability of the parallel DC/DC converters system. When the system reduces cable resistance or increases the remote feedback sensing weighting factor, a severe notch will occur at the frequency response of the output feedback impedance and leads to affect the voltage loop gain of the DC/DC converter in the parallel operation. In order to investigate the aforementioned detrimental effect, the two-port network model of the buck-derived DC/DC converter was deduced based on the interested input-output variables of the designed parallel DC/DC converters system. Accordingly, the control block diagram of the parallel DC/DC converters system with primary droop current-sharing control and remote feedback sensing scheme was built for studying the performance of the interconnection system. Simetrix/Simplis spice-based model was used firstly to find the effects of the varied output cable resistance and remote feedback sensing weighting factor, and further verified by Matlab computation model. The design method of a simple controller, which integrates voltage with droop current-sharing control, the steady-state output voltage droop characteristic and some experimental results are also provided in this study.