Uniform voltage distribution control for Series-Input Parallel-Output, connected converters

This paper(1,2) extends the application of current-mode, shared-bus converters to power system architectures configured as Series-Input, Parallel-Output (SIPO). By employing a SIPO interconnect method, current-mode commercial-off-the-shelf (COTS) dc-dc converters can transform higher input voltages into low output voltages, provide flexible options for power system expansion, and preserve system efficiencies equal to that obtained from standalone converters. However, without proper control, converter internal component mismatch cause the input voltage to be non-uniformly distributed. System reliability suffers as a result of thermal overstress to the converters that contribute a greater portion of the input power. Conversely, robust system stability and uniform input voltage distribution among series-connected converters is realized through input voltage distribution control. Through computer simulation and experimental prototype the uniform voltage distribution power converter architecture is validated and successfully applied.