Analysis, design, and performance evaluation of droop current-sharing method

The droop current sharing method is analyzed, and a general design procedure is proposed. It is shown that the current-sharing accuracy of N+1 power supplies is a function of the output-voltage set-point accuracy, the slope of the output-voltage droop, and gains of the control loop. It was found that to achieve a current sharing accuracy of 10% the output voltage of the paralleled power supplies needs to be set within 0.35%. The accuracy of the design procedure was compared against measured results of three power supplies operating in parallel.